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Leading Edge Materials To Participate In Graphite And Graphene Anode Research Project

Posted By Graphene Council, Thursday, July 2, 2020
Leading Edge Materials announces the participation of its subsidiary Woxna Graphite AB in the newly launched research project “Graphite and graphene as battery electrodes” (the “Project”) which is part of the Vinnova funded competence centre Batteries Sweden (“BASE”).

The Project will research the utilization of natural graphite for battery applications through determination of functionality of the natural graphite in batteries, the addition of silicon to the graphite particles, long-term stability and characterization and optimization of the surface chemistry. The latter will look at innovative technologies for tailoring of the surface chemistry by for example surface coatings, covalent functionalization and artificial Solid Electrolyte Interphases.

BASE was created as an alliance for ultrahigh performance batteries with a long-term vision to address the energy storage challenges associated with the transition to a fossil-free society by developing new types of lightweight, inexpensive, sustainable and safe ultra-high-energy storage batteries. The competence centre, coordinated by the Ångström Laboratory and the renowned battery scientist Professor Kristina Edström at Uppsala University, was granted SEK 34,000,000 in funding by the Swedish governmental innovation agency Vinnova. The partners of BASE are leading Swedish academic institutions and industrial companies spanning the battery value chain; Uppsala University, Chalmers University of Technology, KTH Royal Institute of Technology, RISE Research Institutes of Sweden, ABB, Volvo, Altris, Comsol, Graphmatech, Insplorion, Northvolt, SAFT, Scania, Stena Recycling, Volvo Cars and Woxna Graphite. (https://www.batteriessweden.se/)

Filip Kozlowski, CEO states “Being part of this project is a great opportunity for Woxna Graphite to contribute to the long-term vision of the Batteries Sweden alliance. Being able to supply natural graphite from Sweden could enable sustainable high-performance battery materials of the future. One of the focus areas, surface modification of spherical purified natural graphite is a key area of innovation to enable improved performance and cycle life for lithium-ion battery anodes.”

Woxna Graphite AB is the owner of one of the western world’s few permitted and fully built graphite mines, located in central Sweden near the town of Edsbyn. The Woxna graphite mine and production facility is comprised of four graphite deposits each with a mining lease, an open pit mine, a processing plant and tailings dam, located close to the town of Edsbyn, Sweden.  Due to market conditions for traditional graphite markets the operation has been kept on a production-ready basis. Ongoing development is directed towards test work focused on the possible production and modification of high purity graphite using thermal purification technologies for emerging high growth high value markets, one such example being the lithium-ion battery industry.  Other potential high-value end-markets being investigated are purified micronized graphite for metallurgical and electroconductive additives and purified large flake graphite as a precursor for the production of expandable graphite suitable as a feed for graphite foils and fuel cell bipolar plates. The purification and modification of natural graphite is very energy intensive and having access to low cost low carbon footprint hydropower offers the potential to become a market leader in terms of sustainability.

Tags:  Batteries  Filip Kozlowski  Graphene  Graphite  Leading Edge Materials  Woxna Graphite AB 

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Gridtential Energy and LOLC Advanced Technologies Team up on New Bipolar Battery Technology

Posted By Graphene Council, Wednesday, June 24, 2020
Gridtential Energy, the inventor and developer of Silicon Joule™ bipolar battery technology and LOLC Advanced Technologies, the research and advanced technology arm of LOLC Group announce that they have entered into a technology evaluation agreement.

Under the agreement, over the next few months, LOLC Advanced Technologies and Gridtential Energy will collaborate on prototyping lead batteries with the combined advantages of Silicon Joule™ bipolar silicon plates and AltaLABGX, the Graphene battery additive applied to active materials, supplied by Ceylon Graphene Technologies, CGT (a joint venture between the LOLC Group and Sri Lanka Institute of Nanotechnology (SLINTEC). Preliminary work indicates that the combination of these elements will lead to higher performing batteries in energy density, charging rates and cycle life.

Silicon Joule™ bipolar technology has created an innovative class of lead batteries with silicon at its core. It is a design driven, low cost, high performance, patented energy storage solution that provides improved power density, cycle life, dynamic charge acceptance and temperature range, with up to 40% lower weight, while retaining full lead-battery recyclability. This is all accomplished while leveraging existing technologies from mature industry supply chains – allowing rapid adoption of existing lead-battery infrastructure.

"We are pleased to be working with LOLC Advanced Technologies and Ceylon Graphene Technologies, leaders in battery manufacturing solutions and graphene battery additives respectively. We expect that leveraging leading-edge electro chemistry with our highly efficient Silicon Joule bipolar design will produce industry leading performance with significantly lower weight," said Gridtential Energy CEO, John Barton. "Whether it is longer cycle-life or greater charge/discharge performance, Gridtential is changing the way that OEMs in automotive, 5G telecom, and stationary power markets think about high-performance, low-cost, safe energy storage.

"Every day, we are making it easier to leap into the Silicon Joule Technology future. Whether it is through our rapid prototyping development kits, off-the-shelf reference batteries, equipment manufacturing partners, and now additive experts, the adoption ecosystem has never been stronger. We are pleased that more and more battery manufacturing companies are taking advantage of our technology - now with Graphene battery additive - to produce lead-based products that can compete with lithium. We are quite confident that first movers will be richly rewarded with commercial success."

With Silicon Joule™ bipolar battery technology from Gridtential Energy, that combines the benefits of lead batteries with silicon-enabled, high performance characteristics, battery manufactures world-wide, will be prepared to meet the challenge.

"Worldwide demand is increasing for superior energy storage systems at the edge and driving innovation. LOLC Advanced Technologies with Ceylon Graphene Technologies are improving battery electro-chemistry with our pure graphene and our advanced manufacturing expertise. Partnering with Gridtential's Silicon Joule bipolar solution will lead the advancements in safe, reliable and higher performing lead batteries," said, Chairman Ishara Nanayakkara, LOLC Group

Tags:  Batteries  Battery  Ceylon Graphene Technologies  Energy Storage  Graphene  Gridtential Energy  Ishara Nanayakkara  John Barton  LOLC Group 

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HKUST Research Team Successfully Discovers New Material Generation Mechanism for Chip Design, Quantum Computing and Noise Reduction

Posted By Graphene Council, Monday, June 8, 2020
The research team of the Hong Kong University of Science and Technology (HKUST) has recently made important progress in the field of new materials. Combining the characteristics of two-dimensional materials and topological materials, the team has for the first time discovered a universal generation mechanism of new materials with "type-II" Dirac cones. Many extraordinary properties of the material are realized in experiments, which addressed the key issue that the material could only be obtained sporadically under stringent limits. This mechanism can guide the preparation of new two-dimensional materials that have specific directional responses to external signals such as electric fields, magnetic fields, light waves, sound waves, etc., and will provide valuable applications for modern electronic communications, quantum computing, optical communications, and even sound insulation and noise reduction materials. 

As a typical representative of two-dimensional materials, since its discovery in 2004, graphene has been regarded as one of the greatest material discoveries in the 21st century. As the thinnest, strongest and most thermally conductive "super material" in the world today, graphene has been widely used in transistors, biosensors and batteries, and its discovery led to the 2010 Nobel Prize in Physics. On the other hand, topological materials, because of the existence of extraordinary properties such as zero-dissipative edge transport, are considered to be the cornerstones of the development of future electronic devices, and their discovery led to the 2016 Nobel Prize in Physics. In fact, graphene is also a topological material, and its extraordinary properties are mostly derived from its topological "Dirac cones". However, the "Dirac cones" in graphene belong to the "type-I" Dirac cones of the theoretical predictions. The more unique "type-II" Dirac cones in the theoretical predictions, because of their strongly directional responses to external signals that the type-I Dirac cones do not have, will bring many more possibilities to the development and applications of electronic devices. However, so far, the "Dirac cone of the second kind" can only be found sporadically in some materials, lacking a systematic generation mechanism.

To address this critical issue, the research team led by Prof. WEN Weijia and Dr. WU Xiaoxiao, from the Department of Physics, for the first time, discovered and successfully implemented the systematic generation mechanism of new two-dimensional materials with type-II Dirac cones based on the relevant theories of two-dimensional materials and topological materials, using the band-folding mechanism (a material-independent, universal principle for periodic lattices). Due to its unique topological bands, its response to external signals is extremely directional, so the two-dimensional materials with type-II Dirac cones have important academic and application values for the designs of high-precision detecting devices of external signals, such as electric fields, magnetic fields, light waves, and sound waves. The systematic design and material independence of this scheme also help to relax the precision requirements for circuit designs, making the design of corresponding electronic products easier and more flexible. The team used acoustic field scanning techniques to directly observe the type-II Dirac cone in acoustics, as well as many of its properties that were only proposed in theories previously.

The success of this experimental study has opened up a new field of researches and applications of two-dimensional materials and topological materials, and brought many more possibilities for the future applications of the new materials. The findings of this study have been published in the renowned journal Physical Review Letters.

The ventilated sound absorbers developed by Prof. Wen’s group based on acoustic metamaterials. The ventilated sound absorbers can simultaneously achieve high-performance sound absorption and air flow ventilation, which is important for noise reduction applications in the environment with free air flows, such as air conditioners, exhaust hoods, and ducts.

"Our findings of the deterministic scheme for type-II Dirac points could profoundly broaden application prospects on fronts such as 5G communications, optical computing such as quantum computing and noise reduction. Our team plans to apply the experimental results to electronic devices such as dedicated chips, new touch control materials, filter modules, wireless transmission and biosensors.” said Prof. Wen, “Also, type-II DPs observed in acoustic waves suggest viable new materials for sound barriers, providing potential solutions for high-efficiency soundproofing walls. While we improve the performance of acoustic metamaterials, we will seek to continuously expand their applications in aspects ranging from low-frequency sound absorption, noise reduction in ventilation systems, intelligent active noise cancelling, traffic noise abatement to architectural acoustics. We also hope that these materials can be truly industrialized.”

Long engaged in researching the field of advanced materials, Prof. Wen and his team have made a range of key achievements in the basic and applied research of new materials science. In 2014, he was awarded second-class 2014 State Natural Science Award (SNSA) for the project on "Structural and Physical Mechanism Investigation for Giant Electrorheological Fluid".

Tags:  Batteries  biosensors  Graphene  Hong Kong University of Science and Technology  transistor  WEN Weijia  WU Xiaoxiao 

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Morrow Batteries to build the first giga battery cell factory in Norway

Posted By Graphene Council, Thursday, June 4, 2020
Morrow Batteries will in the coming years build and rapidly scale up battery cell production in Norway in order to meet increasing market demand and lead the drive for more sustainable batteries.

Dual-track technology strategy
To meet the rapidly increasing demand Morrow will initially manufacture cells based on the currently best available technology. However, Morrow inherits a technology platform which will, within the next decade, enable the factory to produce batteries that would be more sustainable, more cost effective and have better performance than the current generation of battery technology.

Green and cost-competitive cell factory
The giga battery cell factory will be located in the Agder region in the south of Norway which has a significant surplus of competitively priced renewable energy. It is also very close to a number of suppliers of critical raw materials and key European markets. This will enable the factory to become both highly cost competitive and one of the greenest battery factories in the world. Significant amount of upstream processes such as precursor preparation and active material synthesis, to the actual cell manufacturing and close loop recycling, will be 100% powered by renewable energy.

The Agder region also has a long tradition and a strong base of globally competitive electro-chemical process industry. This will help secure the factory with a highly skilled and experienced workforce.

Strong and committed industrial owners
The two lead investors of Morrow are Agder Energi and NOAH, owning 39% and 40% respectively. Agder Energi is one of the largest producers of renewable energy in Norway. It is partly owned by Statkraft, Norway’s state-owned renewable power producer, and a number of municipalities in Agder county. NOAH is an industrial company owned by the investor Bjørn Rune Gjelsten, who has a long history of building industry in Norway.

Towards a more sustainable battery
One of the key tenets of Morrows strategy is to significantly improve the environmental impact of batteries. Morrow’s strong environmental focus reflects the fact that one of the initiators of Morrow is the environmental foundation Bellona and its founder Frederic Hauge. Bellona has a long history and commitment to the environmental cause since it’s foundation in 1986.

As early as 1988, Frederic Hauge and Bellona imported the first electric car to Norway together with the well-known pop group A-ha in their fight for electrification, resulting in a range of favorable regulatory changes for electric cars. 20 years later, in 2009, he met with Elon Musk and Tesla. He then became convinced that the battery revolution for cars was here. Bellona teamed up with Tesla to introduce the company to the Norwegian and European market. Tesla choose to start up Tesla sales in Norway as one of first countries outside USA and has since been a success story. It is safe to say that the sustained effort from Bellona has speed up the transition to electric cars.

In 2010, Bellona started to scout for more environmentally friendly ways to produce batteries. As part of this process, Bellona came across Graphene Batteries which was working on Lithium-Sulfur technology development. Graphene Batteries has since achieved significant technological breakthroughs that have been independently validated by Fraunhofer, Europe's largest application-oriented research organization.

In 2017, Bellona became partner and co-owner of Graphene Batteries through the company BEBA, with NOAH as a seed investor. In 2020, BEBA, NOAH and Graphene Batteries joined forces with Agder Energi to establish Morrow Batteries. BEBA will continue as the Bellona Foundation’s company to accelerate battery ventures and industry.

Tags:  Agder Energi  Batteries  Graphene  Morrow Batteries 

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Graphene masks: facing up to coronavirus (COVID-19)

Posted By Graphene Council, Wednesday, May 20, 2020
Since the development and isolation of graphene by researchers at Manchester University in 2004, the “2D miracle material” has been put to use in everything from airplanes to anti-corrosive paints, from batteries to body armour (read our earlier blogs Graphene: a new '2D' world and Advanced materials: game-changing graphene). Unsurprisingly, the wonder material is now being put to work in the global fight against COVID-19.

Graphene has been investigated in various biosensor set-ups, including nucleic acid sequencing devices (see the paper Graphene nanodevices for DNA sequencing published in the journal Nature) and diagnostic devices for the monitoring and treatment of HIV (see Graphene-info). Recently, Korean researchers have developed a graphene-based FET biosensor which can detect the SARS-CoV-2 spike protein (the protein on the surface of the COVID-19 virus) from patients’ swabs in less than a minute (see Graphene-info).

However, one key issue in the fight against COVID-19 is maintaining a supply of high quality protective equipment such as masks, gloves and gowns for medical staff.

Among graphene’s myriad of useful properties is its antimicrobial activity attributed, among other reasons, to graphene’s ability to perturb membranes. Several teams have taken advantage of graphene’s antimicrobial, antistatic and electrically conductive properties to develop face masks which can be re-sterilised and, importantly, reused.

For example, IDEATI have developed a cotton fabric facemask with a coating containing both graphene and other carbon nanomaterials. The coating on the mask has been shown to reduce levels of Staphylococcus aureus bacteria by 99.95% within a 24 hour period. The graphene coating also repels dust and is effective against airborne particles of less than 2.5 microns in diameter. The mask can be washed and reused up to 10 times without losing its antibacterial or antistatic properties. The product has currently only been shown to be effective against bacteria. However, IDEATI are currently evaluating the masks antiviral properties (see Graphene-info).

An innovative approach to PPE
Taking a slightly different approach, LIGC Applications have recently launched a graphene-based respirator mask which claims to compete with gold standard N95 respirator masks. N95 respirator masks are used by medical staff as part of their PPE (personal protective gear) and can block 95% of particles over 0.3 microns. However, the COVID-19 virus is approximately 0.2 microns in diameter and can still be transmitted in tiny water droplets of less than 0.3 microns in size (see Graphene-info).

LIGC Applications’ “Guardian G-Volt” mask is allegedly 99% efficient against particles over 0.3 microns, as well as being 80% efficient against anything smaller. The mask has an electrically embedded graphene filtration system formed from laser-induced graphene, a microporous foam which is conductive and can trap pathogens.

The mask, powered by a portable battery pack which is plugged into the mask via a USB port, works by applying a low level electric charge to the surface to sterilise it and repel particles trapped in its graphene filter. The mask also has an LED light which alerts the user when the mask needs to be replaced. N95 masks must be disposed of once they become damp, however, the Guardian G-Volt can be heated and sterilised in a home docking system, which allows the mask to be safely reused.

Of course, wearing a mask alone will not give absolute protection against pathogens, such as the COVID-19 virus. But these advances illustrate that there are a plethora properties of graphene which can be utilised in different ways to achieve a common goal.

Tags:  Batteries  Graphene  Healthcare  nanodevices  Sensors 

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New Graphene Supercapacitor Materials Offer Fast Charging for Electric Vehicles

Posted By Graphene Council, Monday, May 18, 2020
Introduction

Picture the scene, you are driving to a meeting and running late. The new company car is an electric vehicle (EV), power is running low and range anxiety is setting in. You pull into the service station on the motorway and head straight to the charging station. Instead of taking hours to charge, the car is fully charged in minutes. You pay at the fuel court and back on your way to the meeting in under 5 minutes. Welcome to the future.  Welcome to the world of graphene supercapacitors.

Batteries

We have seen dramatic improvements in battery technologies over recent years but range anxiety and the need for large battery powertrains for performance and commercial vehicles means that EV’s still have some way to go before they are universally accepted. EV’s are calling out for lightweight and more powerful powertrains. Capacitors and supercapacitors could be the answer.

Capacitors and Supercapacitors

Batteries provide high energy density, which means that they have the ability to provide power over a longer period, but they have low power density. Capacitors have a lower energy density but have a high power density and can charge and discharge very quickly providing high bursts of power when required.  In short, batteries are able to store more energy but capacitors can release energy more quickly.

Supercapacitors are generally categorised into three groups : electrostatic double-layer capacitors (EDLCs) using carbon electrodes, electrochemical pseudo-capacitors which use metal oxide or conducting polymer electrodes and hybrid capacitors such as the lithium-ion capacitor.  These differing electrodes – the first exhibiting mostly electrostatic capacitance and the others offer some chemical performance.

Supercapacitors, or ultracapacitors as they are sometimes called could be used in conjunction with batteries to provide powertrains at a reduced weight. Supercapacitors have the ability to tolerate high charge and discharge cycles and are capable of storing and discharging energy very quickly and effectively.  They can hold a much higher charge than traditional capacitors.  In vehicles, supercapacitors are predominantly used for regenerative braking.

Why are supercapacitors becoming important?

Lithium-ion battery technology has made huge advances and industry continues to make incremental improvements however, these do not meet the needs of the electric vehicle industry in terms of range, weight and cost. Supercapacitors can complement the chemical battery by providing bursts of energy when required, such as moving a large truck from a standing stop or short-term surge of power to accelerate a high-performance sports car.  Combining both battery and supercapacitor technologies into a new hybrid battery could satisfy both short and long-term power needs, reducing stress on the battery at peak loads, leading to longer service life.  Potentially, this could lead to smaller, lighter battery packs and vehicles due to supercapacitors taking part of the load and extending the range of EV’s.

Examples of Supercapacitor Applications

• Private and public electrical vehicles
• Port-cranes
• Automotives
• Rail sectors
• Grid energy storage
• Smart phones
• Other consumer electronics
• Sensors
• Wireless sensor networks
• Stationary storage
• Renewables integration
• Industrial vehicles
• Electric & hybrid buses
• Replacement for lead-acid batteries in trucks
• Provide burst of power in lifting operations – cranes, diggers etc.
• Provide fast flow of energy to data centres between power failures and initiation of backup power systems
• Uninterruptible Power Systems (UPS) – for back-up power systems, for example in data centres
• Actuators (Aircraft emergency doors)
• Work in conjunction with lithium-ion batteries or lead-acid batteries in vehicles like forklifts

Why Graphene-based supercapacitors?

It is clear that supercapacitors are a promising supplement to lithium-ion batteries, offering significantly high-power densities, resilience to multiple charge/discharge cycles and short charging times. However, growth in the supercapacitor market may be stifled by the limited capacitance of current materials and the inability of suppliers to effectively scale-up production. Graphene-based materials are a highly suitable alternative to these technologies.

Graphene-based capacitors are lightweight and have a relatively low-cost vs performance ratio.  Graphene lends far more strength compared with activated carbon.  In addition, graphene has a surface area even larger than that of activated carbon used to coat the plates of traditional supercapacitors, enabling better electrostatic charge storage. Graphene-based supercapacitors can store almost as much energy as lithium-ion batteries, charge and discharge in seconds and maintain these properties through tens of thousands of charging cycles.

Professors at the University of Manchester have developed an electrochemical process that enables the production of microporous, metal oxide-decorated graphene materials from graphite. Conventional activated carbon has a gravimetric capacitance of 50-150 Farads per gram, whereas laboratory trials show that these new graphene materials demonstrate a gravimetric capacitance of up to 500 Farads per gram.

Tags:  Batteries  electric vehicle  Graphene  Graphite  Li-ion batteries  supercapacitors  University of Manchester 

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New Fund Provides More Than $1.3 Million for Research Commercialization

Posted By Graphene Council, Monday, May 11, 2020
The Chancellor’s Commercialization Fund has provided more than $1.3 million in funding to University of Arkansas researchers seeking to bring new technologies to the marketplace.

Established in March 2019, the fund has awarded 33 grants ranging anywhere from $5,000 to $50,000. The fund prioritizes aggressive teams with mature projects who are “progressing technologies toward real-world applications, providing critical, commercially relevant data or developing working prototypes.”

These grants have been used to provide support for postdoctoral students, graduate assistants, materials, travel expenses and other costs.

The $1 million annually allotted to the Commercialization Fund was made possible by a larger $23.7 million gift from the Walton Family Charitable Support Foundation to support research and economic development at the university and is administered by the Office of Economic Development.

One goal of the gift is to increase the university’s research volume by investing in highly productive faculty, research infrastructure and signature research areas developed by the Office of Research and Innovation.

As Chancellor Joe Steinmetz wrote in his Focus on the Future series, “Simply stated, the higher your research volume, or expenditures, the more likely you are to generate intellectual property with commercial applications.” As such, the grant also provides for additional investment in staff, programs, operations and outreach related to economic development and the commercialization of research.

Stacy Leeds, vice chancellor for economic development, said of the Commercialization Fund, “As envisioned, dozens of faculty have been able to transform an idea toward real-world application, often in partnership with a private sector partner."

One recipient of a commercialization grant was physics professor Paul Thibado, whose research led him to the discovery that naturally occurring graphene vibrations can be used to generate electricity.

Thibado saw there were commercial applications, but they involved designing and manufacturing silicon-based circuits, which was outside his area of expertise. Thibado explained, “Having access to the commercialization funds enabled me to bring others in to move the project forward. As a result, we are much closer to successfully developing a chip that can power miniature devices without using batteries.”

The Commercialization Fund is a subset of the larger Chancellor’s Fund. Three other funding categories are also available to U of A faculty: the Innovation and Collaboration Fund, which provides seed funding to support bold thinking and risk taking in connection with the university’s signature research areas; the Gap Fund, which provides start-up support for teams that have completed National I-Corps training; and the Humanities and Performing Arts Fund, which supports creative activity and innovation in the humanities and performing arts.

Tags:  Batteries  Graphene  Paul Thibado  University of Arkansas 

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KIST develops stretchable lithium-ion battery based on new micro-honeycomb structure

Posted By Graphene Council, Thursday, April 30, 2020
The microscale reentrant-honeycomb shaped, graphene-based electrode is characterized by an accordion-like structural stretchability. A stretchable gel electrolyte and stretchable separator are also developed for all-component stretchable full cells, applying for future stretchable devices.

A Korean research team has developed a lithium-ion battery that is flexible enough to be stretched. Dr. Jeong Gon Son's research team at the Photo-Electronic Hybrids Research Center at the Korea Institute of Science and Technology (KIST) announced that they had constructed a high-capacity, stretchable lithium-ion battery. The battery was developed by fabricating a structurally stretchable electrode consisting solely of electrode materials and then assembling with stretchable gel electrolyte and stretchable packaging.

Rapid technological advancements in the electronics industry have led to a fast-growing market for high-performance wearable devices, such as smart bands and body-implantable electronic devices, such as pacemakers. These advancements have considerably increased the need for energy storage devices to be designed in flexible and stretchable forms that mimic human skin and organs.

However, it is very difficult to impart the stretchability to the battery because the solid inorganic electrode material occupies most of the volume, and other components such as current collectors and separators must also be made stretchable. In addition, the problem of liquid electrolyte leakage under deformation also should be solved. , and the problem of leaking the liquid electrolyte must also be solved.

In order to address these problems, Dr. Jeong Gon Son's research team at KIST focused on creating an accordion-like micro-structure, which gives structural stretchability to non-stretchable materials, and thus constructed a micro-inwardly curved electrode framework in a honeycomb shape. The inwardly protruded honeycomb framwork consisted of atom-thick graphene, which serves as an curtain, and carbon nanotubes, which formed a nano-size rope. The honeycomb-shaped composite framework, made of active materials, graphene, and carbon nanotubes, was inwardly protruded like an accordion using a radial compression process, resembling the rolling of Korean rice rolls (gimbap), which resulted in the creation of stretchable properties.

The electrodes developed by the research team do not contain any materials typically used for stretchability, such as rubber, that do not facilitate energy storage. All of the materials used by the research team in their newly developed battery are fully utilized in energy storage and charge transport. In fact, the stretchable battery created by the team showed an energy storage capacity (5.05 mAh/cm2) that is as high as existing non-stretchable batteries.

The KIST newly introduced stretchable gel electrolytes and stretchable packaging materials, that block air and moisture, and keep the electrolytes from leaking. The resulting stretchable battery showed a high areal capacity of 5.05 mAh?cm?2, superior electrochemical performance up to 50% strain under repeated (up to 500) stretch-release cycles and long-term stability of 95.7% after 100 cycles in air conditions.

Dr. Jeong Gon Son at KIST said, "The stretchable lithium-ion battery developed through this research is expected to present a new paradigm in term of stretchable energy storage systems for the further development of wearable and body-implantable electronic devices."

Tags:  Batteries  Graphene  Jeong Gon Son  Korea Institute of Science and Technology 

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Wetting property of Li metal with graphite

Posted By Graphene Council, Thursday, March 12, 2020
"Rock-chair" Li-ion battery (LIB) was discovered in the late 1970s and commercialized in 1991 by Sony, which has become the priority way we store portable energy today. To honor the contribution for "creating a rechargeable world", the 2019 Nobel Prize in chemistry was awarded to three famous scientists (John B. Goodenough, M. Stanley Whittingham, Akira Yoshino) who made the most important contributions to the discovery of LIBs. However, this technology is nearing its practical performance limits and extensive efforts are underway to replace LIBs with new electrochemical storage solutions, which are safe, stable, low cost and with higher energy density to power long-range electric vehicles and long-lasting portable electronics.

Replacing the traditional graphite-based anodes with Li metal, a "holy" anode with a high theoretical capacity of 3860 mAh/g, shows it a promising approach. At present, Li metal anode suffers from poor cycling efficiency and infinite volume change, raising operational safety concerns. Effective efforts include functional electrolyte additive, artificial solid-electrolyte interface and using host scaffolds to buffer the volume expansion have been taken to tackle its disadvantages. Among these, the method of using scaffolds continues to see rapid development.

Graphite, a classic Li anode, shows a great promising as an effective host scaffold, which possesses a low density and high electron conductivity. However, it is generally accepted that Li metal wets graphite poorly, causing its spreading and infiltration difficult. Previous methods to transforming graphite from lithiophobicity to lithiophilicity include surface coating with Si, Ag or metal oxide (lithiophobic indicates a large contact angle, while lithiophilic indicates a low contact angle between molten lithium and solid surface). However, such a change in liquid spreading behavior is due to the replacement of graphite by reactive coating. Consequently, it might be asked whether graphite is intrinsically lithiophobic or lithiophilic.

Herein, the wetting behavior of molten Li on different kinds of graphite-based carbon materials were systematically studied. Firstly, the highly oriented pyrolytic graphite (HOPG) was used as the test sample (Figure a). It is observed that HOPG substrate immediately allows an contact angle (CA) of 73° with Li metal (Figure b, c). To check this experiment against theory, ab initio molecular dynamics simulation was performed with a molten Li droplet (54 Li atoms)/graphite (432 C atoms, two-layered graphene) setup to prove that a clean (002) surface of graphite is intrinsically lithiophilic at 500K and the results also confirmed that lithium and graphite have good affinity.

However, the CA of Li metal on porous carbon paper (PCP, Figure d) is as high as 142°, which indicates PCP is lithiophobic (Figure e and f). This result which contradicted with previous conclusion that graphite is intrinsically lithiophilic prompted researchers to gain further understanding of the effect of surface chemistry to the wetting performance of Li metal and graphite. Compared with HOPG, it is found that PCP surface has a large number of oxygen-containing functional groups. These surface impurities will play a key role in pinning the contact line between Li metal and PCP, resulting in a lager apparent contact angle.

In order to demonstrate this assumption, the PCP was first lithiated by decreasing its electrochemical potential with molten Li metal (Figure g). During this process, the surface impurities of PCP will be eliminated as well. The following experiment shows that lithiated PCP exhibited a small CA of ~52°, which indicated a successful transition from lithiophobicity to lithiophilicity. Due to its porous structure of lithiated PCP, the Li metal rapid diffused through (Figure h and i). The DFT simulation revealed that lithiated graphite and graphite possessed similar wetting performance, demonstrating the elimination of the surface impurities would be the key reason for this transition of wetting performance from PCP to lithiated PCP. The graphite powder is further used to test its wettability with Li metal. After continue mixing, the graphite powder could be uniformly dispersed in the Li metal matrix, further confirming a lithiophilic property of graphite. Taking advantage of this discovery, a novel Li metal-graphite compositing method was proposed and Li-graphite composite anode with large area can be produced in a large scale.

This work not only systematically studies the wettability of Li metal and graphite-based carbon materials, but also provides a novel idea for the construction of Li-carbon composite anode materials, which is helpful for the development of high-energy Li metal batteries.

Tags:  batteries  Graphene  graphite  Li-ion batteries  lithium 

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Global Graphene Group Named R&D 100 Award Finalist

Posted By Graphene Council, Friday, January 17, 2020
Global Graphene Group (G3) was honored recently by R&D World, naming G3’sgraphene-protected lithium metal anode for rechargeable metal batteries solution (HELiX™) a finalist for the 2019 R&D100 Award. The R&D 100 Awards recognize the top 100 most technologically significant new products of the year. 

HELiX is a single-layer graphene-protected lithium metal technology making high-energy rechargeable metal batteries viable. It allows extremely low anode usage (anode/cathode ratio ≤ 10%), creating an energy density over 350 Wh/kg and 1,000 Wh/L, which yields a 60-80% improvement over current lithium-ion batteries. This offers unprecedented opportunities for advanced portable devices/electric vehicles.

HELiX is a readily available, drop-in, graphene-enabled anode solution for all types of high-energy, lithium metal batteries (e.g. advanced Li-ion, all solid-state batteries, Li-S, Li-Se, and Li-air cells). It adds immediate value to any rechargeable battery, including, but not limited to power drones, renewable energy storage systems, aerospace applications, unmanned vehicles, and electric vehicles (EVs). Additionally, due to its performance, batteries can be reduced in size by 30-40% while still providing the required energy. This provides room for other components or allows for significant reductions in size and weight.  The most promising opportunity for HELiX graphene-enabled anode solutions is inEV batteries, where it can replace incumbent (graphite) technology today and drive an accelerated adoption of EVs due to improved cost and performance. 

“Rechargeable lithium metal batteries for next-generation portable devices and EVs must meet several challenging requirements: safety, high energy density, long cycle life, and low cost.This is the end-goal laid out by nearly every EV manufacturer for the foreseeable future,” said Dr. Aruna Zhamu, VP of New Product / Process Development at G3. 

“Global Graphene Group has developed an enabling anode-protecting technology that is essential to successful operation of safe, high-energy and long-cycle-life lithium metal batteries working with liquid, quasi-solid, or solid electrolytes,” continued Dr. Zhamu.“This HELiX product has overcome the long-standing issues thus far impeding successful commercialization of all the rechargeable batteries that make use of lithium metal as the anode material. OurHELiX technology is available and offers a drop-in, scalable, facile, cost reducing improvement over current solutions. It lowers the battery cost to less than$100 US$/kWh.”

G3 developed and produces the HELiX solution in its Dayton, Ohio, facilities. G3 was named an R&D 100 winner in 2018 for its graphene-enabled silicon anode (GCATM).

Tags:  Aruna Zhamu  Batteries  electric vehicle  Energy Storage  Global Graphene Group  Graphene  Li-Ion batteries  Lithium 

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