You are here

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.

Graphene structure photo

In the field of batteries, conventional battery electrode materials (and prospective ones) are significantly improved when enhanced with graphene. Graphene can make batteries that are light, durable and suitable for high capacity energy storage, as well as shorten charging times. It will extend the battery’s life-time, 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 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 supercapacitors could yield amazing results, like the noted concept of improving the electric car’s driving range and efficiency.

Battery basics

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.

Eneloop battery design

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.

Li-Polymer battery vs Supercapacitor structure

Commercial Graphene-enhanced battery products

Graphene-based batteries have exciting potential and while they are not commercially available yet, R&D is intensive and will hopefully yield results in the future.

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.

Vorbeck Vor-power photo

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.

Graphene batteries market report

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. Called EMotion, the electric sports car will reportedly achieve a 161 mph (259 kmh) top speed and a 400-mile electric range.

Graphene Nanochem and Sync R&D’s October 2014 plan to co-develop graphene-enhanced Li-ion batteries for electric buses, under the Electric Bus 1 Malaysia program, is another example.

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.

UK based Perpetuus Carbon Group and OXIS Energy agreed in June 2014 to co-develop graphene-based electrodes for Lithium-Sulphur batteries, which will offer improved energy density and possibly enable electric cars to drive a much longer distance on a single battery charge.

Another interesting venture, announced in September 2014 by US based Graphene 3D Labs, regards plans to print 3D graphene batteries. These graphene-based batteries can potentially outperform current commercial batteries as well as be tailored to various shapes and sizes.

Other prominent companies which declared intentions to develop and commercialize graphene-enhanced battery products are: Grafoid, SiNode together with AZ Electronic Materials, XG Sciences, Graphene Batteries together with CVD Equipment and CalBattery.

Further reading

Latest Graphene Batteries news

Talga enters agreement with Zinergy to develop graphene inks for printed flexible bateries

Mar 22, 2017

Talga Resources logoTalga Resources, an Australia-based company focused on graphite mining and graphene supply and applications development, has announced that it has signed a joint development agreement with Zinergy UK to co-develop and supply graphene conductive inks for electrodes in thin, flexible printed batteries.

Under the terms of the agreement, Talga and Zinergy will collaborate to develop and trial graphene-based conductive ink formulations in components of the patented Zinergy ultra-thin printed battery. The development program will run for an initial 12 month period.

A new graphene oxide coating to improve the performance of lithium-sulfur batteries

Mar 21, 2017

Researchers at Yale University have developed an ultra-thin coating material, based on graphene oxide, that has the potential to extend the life and improve the efficiency of lithium-sulfur batteries. The newly developed material is a dendrimer-graphene oxide composite film, that can be applied to any sulfur cathode.

GO coating to improve Li-sulfur batteries performance image

The researchers state that sulfur cathodes coated with the material can be stably discharged and recharged for more than 1,000 cycles, enhancing the battery’s efficiency and number of cycles. In addition, they said “the developed film is so thin and light it will not affect the overall size or weight of the battery, and thus it will function without compromising the energy and power density of the device”.

Graphene for the Display and Lighting Industries

Grafoid unveils GPURE graphene membrane for Li-ion batteries

Mar 15, 2017

Grafoid logoGrafoid, the Canadian graphene R&D, investment and technology company, announced the development of its GPURE Graphene Polymer nano-porous membrane intended for next generation Li-Ion battery applications.

The GPURE graphene polymer membrane (GPM) was developed as a chemically inert, freestanding membrane using graphene composites to test ion selectivity using both monovalent and divalent ions. Ion selectivity is a key requirement for a semi permeable membrane in a Li-ion battery structure. By protecting the sensitive electrode materials from unwanted chemical species GPURE GPM diffuses only energy harvesting monovalent ions such as Li+, Na+ etc.

China's Chowei Power announces graphene-enhanced lead-acid battery

Mar 09, 2017

Update: Our sources in china say that it is highly unlikely that this battery actually has any graphene materials in it...

Chinese battery manufacturer Chaowei Power launched a new version of its Black Gold battery — a lead-acid battery that reportedly uses graphene as an additive. The company states that the battery resistance is reduced by 52% and that performance of the battery in low temperature operations has been greatly improved.

Chowei's graphene batteries

Chaowei makes lithium and lead acid automotive batteries under the Chilwee brand. Its Black Gold high-energy VRLA series was launched in February 29, 2016, when it reportedly first applied graphene technology to a commercial, mass-produced rechargeable lead battery.

Graphene-Info's Batteries, Supercapacitors, GO, Lighting, Displays and Graphene Investments Market Reports updated to March 2017

Mar 06, 2017

Today we published a new version of all our graphene market reports. Graphene-Info provides comprehensive niche graphene market reports, and our reports cover everything you need to know about these niche markets. The reports are now updated to March 2017.

Graphene batteries market report 3D cover

The Graphene Batteries Market Report:

  • The advantages using graphene batteries
  • The different ways graphene can be used in batteries
  • Various types of graphene materials
  • What's on the market today
  • Detailed specifications of some graphene-enhanced anode material
  • Personal contact details into most graphene developers

The report package provides a good introduction to the graphene battery - present and future. It includes a list of all graphene companies involved with batteries and gives detailed specifications of some graphene-enhanced anode materials and contact details into most graphene developers. Read more here!