Graphene and batteries
Graphene, a sheet of carbon atoms bound together in a honeycomb lattice pattern, is hugely recognized as a “wonder material” due to the myriad of astonishing attributes it holds. It is a potent conductor of electrical and thermal energy, extremely lightweight chemically inert, and flexible with a large surface area. It is also considered eco-friendly and sustainable, with unlimited possibilities for numerous applications.
In the field of batteries, conventional battery electrode materials (and prospective ones) are significantly improved when enhanced with graphene. A graphene battery can be light, durable and suitable for high capacity energy storage, as well as shorten charging times. It will extend the battery’s life, which is negatively linked to the amount of carbon that is coated on the material or added to electrodes to achieve conductivity, and graphene adds conductivity without requiring the amounts of carbon that are used in conventional batteries.
Graphene can improve such battery attributes as energy density and form in various ways. Li-ion batteries (and other types of rechargeable batteries) can be enhanced by introducing graphene to the battery’s anode and capitalizing on the material’s conductivity and large surface area traits to achieve morphological optimization and performance.
It has also been discovered that creating hybrid materials can also be useful for achieving battery enhancement. A hybrid of Vanadium Oxide (VO2) and graphene, for example, can be used on Li-ion cathodes and grant quick charge and discharge as well as large charge cycle durability. In this case, VO2 offers high energy capacity but poor electrical conductivity, which can be solved by using graphene as a sort of a structural “backbone” on which to attach VO2 - creating a hybrid material that has both heightened capacity and excellent conductivity.
Another example is LFP ( Lithium Iron Phosphate) batteries, that is a kind of rechargeable Li-ion battery. It has a lower energy density than other Li-ion batteries but a higher power density (an indicator of of the rate at which energy can be supplied by the battery). Enhancing LFP cathodes with graphene allowed the batteries to be lightweight, charge much faster than Li-ion batteries and have a greater capacity than conventional LFP batteries.
In addition to revolutionizing the battery market, combined use of graphene batteries and graphene supercapacitors could yield amazing results, like the noted concept of improving the electric car’s driving range and efficiency. While graphene batteries have not yet reached widespread commercialization, battery breakthroughs are being reported around the world.
Batteries serve as a mobile source of power, allowing electricity-operated devices to work without being directly plugged into an outlet. While many types of batteries exist, the basic concept by which they function remains similar: one or more electrochemical cells convert stored chemical energy into electrical energy. A battery is usually made of a metal or plastic casing, containing a positive terminal (an anode), a negative terminal (a cathode) and electrolytes that allow ions to move between them. A separator (a permeable polymeric membrane) creates a barrier between the anode and cathode to prevent electrical short circuits while also allowing the transport of ionic charge carriers that are needed to close the circuit during the passage of current. Finally, a collector is used to conduct the charge outside the battery, through the connected device.
When the circuit between the two terminals is completed, the battery produces electricity through a series of reactions. The anode experiences an oxidation reaction in which two or more ions from the electrolyte combine with the anode to produce a compound, releasing electrons. At the same time, the cathode goes through a reduction reaction in which the cathode substance, ions and free electrons combine into compounds. Simply put, the anode reaction produces electrons while the reaction in the cathode absorbs them and from that process electricity is produced. The battery will continue to produce electricity until electrodes run out of necessary substance for creation of reactions.
Battery types and characteristics
Batteries are divided into two main types: primary and secondary. Primary batteries (disposable), are used once and rendered useless as the electrode materials in them irreversibly change during charging. Common examples are the zinc-carbon battery as well as the alkaline battery used in toys, flashlights and a multitude of portable devices. Secondary batteries (rechargeable), can be discharged and recharged multiple times as the original composition of the electrodes is able to regain functionality. Examples include lead-acid batteries used in vehicles and lithium-ion batteries used for portable electronics.
Batteries come in various shapes and sizes for countless different purposes. Different kinds of batteries display varied advantages and disadvantages. Nickel-Cadmium (NiCd) batteries are relatively low in energy density and are used where long life, high discharge rate and economical price are key. They can be found in video cameras and power tools, among other uses. NiCd batteries contain toxic metals and are environmentally unfriendly. Nickel-Metal hydride batteries have a higher energy density than NiCd ones, but also a shorter cycle-life. Applications include mobile phones and laptops. Lead-Acid batteries are heavy and play an important role in large power applications, where weight is not of the essence but economic price is. They are prevalent in uses like hospital equipment and emergency lighting.
Lithium-Ion (Li-ion) batteries are used where high-energy and minimal weight are important, but the technology is fragile and a protection circuit is required to assure safety. Applications include cell phones and various kinds of computers. Lithium Ion Polymer (Li-ion polymer) batteries are mostly found in mobile phones. They are lightweight and enjoy a slimmer form than that of Li-ion batteries. They are also usually safer and have longer lives. However, they seem to be less prevalent since Li-ion batteries are cheaper to manufacture and have higher energy density.
Batteries and supercapacitors
While there are certain types of batteries that are able to store a large amount of energy, they are very large, heavy and release energy slowly. Capacitors, on the other hand, are able to charge and discharge quickly but hold much less energy than a battery. The use of graphene in this area, though, presents exciting new possibilities for energy storage, with high charge and discharge rates and even economical affordability. Graphene-improved performance thereby blurs the conventional line of distinction between supercapacitors and batteries.
Graphene-enhanced battery products moving towards commercialization
Graphene-based batteries have exciting potential and while they are not yet fully commercially available yet, R&D is intensive and will hopefully yield results in the future.
In December 2018, India-based Log 9 Materials announced that it is working on graphene-based metal-air batteries, that in theory may even lead to electric vehicles that run on water. The metal air batteries use a metal as anode, air (oxygen) as cathode and water as an electrolyte. A graphene rod is used in the air cathode of the batteries. Since Oxygen has to be used as the cathode, the cathode material has to be porous to let the air pass, a property in which graphene excels. According to Log 9 Materials, the graphene used in the electrode is able to increase the battery efficiency by five times at one-third the cost.
In November 2017, Samsung developed a unique "graphene ball" that could make lithium-ion batteries last longer and charge faster. In fact, Samsung Advanced Institute of Technology (SAIT) said that using the new graphene ball material to make batteries will increase their capacity by 45% and make their charging speed five times faster. It was also said that the Samsung battery that will use this graphene ball material will be able to maintain a temperature of 60 degrees Celsius that is required for use in electric cars.
In November 2016, Huawei unveiled a new graphene-enhanced Li-Ion battery that can remain functional at higher temperature (60° degrees as opposed to the existing 50° limit) and offers a longer operation time - double than what can be achieved with previous batteries. To achieve this breakthrough, Huawei incorporated several new technologies - including an anti-decomposition additives in the electrolyte, chemically stabilized single crystal cathodes - and graphene to facilitate heat dissipation. Huawei says that the graphene reduces the battery's operating temperature by 5 degrees.
In June 2014, US based Vorbeck Materials announced the Vor-Power strap, a lightweight flexible power source that can be attached to any existing bag strap to enable a mobile charging station (via 2 USB and one micro USB ports). the product weighs 450 grams, provides 7,200 mAh and is probably the world’s first graphene-enhanced battery.
In May 2014, American company Angstron Materials rolled out several new graphene products. The products, said to become available roughly around the end of 2014, include a line of graphene-enhanced anode materials for Lithium-ion batteries. The battery materials were named “NANO GCA” and are supposed to result in a high capacity anode, capable of supporting hundreds of charge/discharge cycles by combining high capacity silicon with mechanically reinforcing and conductive graphene.
Developments are also made in the field of graphene batteries for electric vehicles. Henrik Fisker, who announced its new EV project that will sport a graphene-enhanced battery, unveiled in November 2016 what is hoped to be a competitor to Tesla. However, the Fisker battery was later announced to not rely on graphene.
In August 2014, Tesla suggested the development of a "new battery technology" that will almost double the capacity for their Model S electric car. It is unofficial but reasonable to assume graphene involvement in this battery.
Many other companies are also working on incorporating graphene into various kinds of batteries, for more information we recommend reading our Graphene Batteries Market Report.
The latest graphene batteries news:
Directa Plus progressed its partnership with U.S-based Lithium Sulphur batteries company NexTech Batteries by signing a 3-year Supply and Strategic R&D agreement for developing next-generation batteries for green mobility, grid storage, aviation and consumer products.
The Supply Agreement, based on a worldwide bilateral exclusivity in the lithium battery field, has an initial duration of three years, with an option to be extended for two years longer. The R&D Agreement, also with a duration of three years, provides for Joint Lab activities with the intention of developing new specific grades of G+ graphene nanoplatelets. Both parties will dedicate selected scientists from their R&D teams and part of their respective facilities to the enterprise.
Graphene-enhanced battery casing developer, Vaulta, enters agreement with Australian aerospace manufacturer
A new Australian battery casing company called Vaulta has announced that it is working with Quickstep, Australia’s largest independent aerospace advanced composites manufacturer, to develop smarter technology for renewables, manned and unmanned drones and electric flight.
The two Australian companies have signed a memorandum of understanding to pair Vaulta’s innovative graphene-enhanced cell casing technology with Quickstep’s manufacturing capability and market reach as it looks to move further into the high-growth market of electric-powered land and air vehicles. The two companies will be actively working together on a joint proposal for Australian Defense.
GAC Group announces that its Aion V, sporting a graphene battery, will start production in September 2021
GAC Group recently announced "a major achievement in battery technology". GAC stated that it achieved breakthrough progress with its graphene-based super-fast-charging battery and has now entered the phase of actual vehicle testing. Aion V, the first vehicle to be equipped with the battery, is undergoing winter testing and is initially scheduled for mass production in September this year.
In May 2020, GAC announced its plan to mass produce graphene-enhanced battery for EVs by the end of 2020, and in September 2020, GAC announced setting up a unit that specializes in graphene that has begun research and development of fast-charging technology for electric vehicles. In November 2020, GAC stated that it expects to test its battery in production vehicles by the end of 2020, however - whether it can eventually be put into mass production will have to await the results of real-vehicle testing. It appears that now, GAC has decided to go forward with its graphene batteries, launching the Aion V in les than a year (if all will go according to its plans).
China Carbon is developing new silicon graphene nanocomposite product for next-gen lithium-ion batteries
China Carbon Graphite Group, Chinese manufacturer of graphene and graphite-based products, has announced that together with the research and development team of its subsidiary, Royal Elite New Energy Science and Technology ("Roycarbon"), the company is developing a new silicon graphene nanocomposite product for next-gen lithium-ion batteries.
This upcoming product is expected to replace the current anode material and would provide improvements in electrochemical performance for the latest EV and mobile device batteries.
Researchers from the Warwick Manufacturing Group (WMG) at the University of Warwick, together with members from the Imperial College London, has enhanced three hybrid flow cells with the use of nitrogen doped graphene - graphene sheets exposed to nitrogen plasma - using a binder-free electrophoresis (EPD) technique.
The new technique could potentially promote wider acceptance and renewable energy sources - such as hydro and solar power - currently limited by intermittency problems that prevent mass adoption of these sources into larger, national-scale power grids. One idea explored in working around this limitation is the use of long-duration battery technologies, like redox flow batteries. However, despite its longevity and performance, current costs have become significant tradeoff considerations and also hampers widespread adoption.