Application of Graphene for Electric Battery driven Vehicle – Technology at Crossroad

  • Home
  • Application of Graphene for Electric Battery driven Vehicle – Technology at Crossroad
Shape Image One
Application of Graphene for Electric Battery driven Vehicle – Technology at Crossroad

Graphene: the wonder material.

It is the strongest, thinnest material known to exist — 20 times stronger than diamond, 200 times stronger than steel and six times lighter. It is also remarkably conductive, both electrically and thermally.

If that isn’t enough, it is also almost perfectly transparent, impermeable to gas, and its properties are, scientists say, easily alterable.

And what is it made of? It’s plain and simple carbon.

Well, it is not the type of carbon, like graphite or diamond that we come across in our day to day use.  Technically, it is a crystalline allotrope of carbon just one atom thick, which makes it virtually two dimensional. It can also be considered an infinitely large polycyclic aromatic compound.

This material was first isolated in 2004 and was immediately noticed by the scientific world. Further research for simple and cost-effective isolation processes as well as identifying and developing its applications continued in major laboratories across the world. In the beginning, the process was quite cumbersome and costly but now has become so simple that (it is claimed) it can be prepared with basic kitchen tools and materials like blenders and soap.

The best thing about graphene is that it has vast application potential. These include lightweight, thin, flexible, yet durable display screens, electric circuits, batteries, solar cells, desalination units, as well as various medical, chemical and industrial processes enhanced or enabled by the use of graphene materials.

Of all the mind-blowing, futuristic applications, I would pick up one that looks quite promising and achievable:

Its application in battery-powered electric vehicles (BEV).

 Graphene has an immense potential to revolutionize the electric car as we see it today. The electric car of today is green i.e. it has much less greenhouse gas emission and it is not dependent on costly and fluctuating imported petrol and diesel prices. But, although this technology is as old as that of IC engine (in fact, it was more popular in the late nineteenth and early twentieth century), the technology never really picked up. Its widespread adoption faces several hurdles like the higher cost of electric vehicles, the lack of recharging infrastructure (other than home charging) and the drivers’ fear that a vehicle has insufficient range to reach its destination and would thus be stranded midway.

Now, let us see how graphene can fit in the picture.

The battery

The electric car derives its power from an onboard rechargeable battery pack and is used for its propulsion. Rechargeable batteries used in electric vehicles include lead-acid (“flooded”, Deep cycle, and VRLA), NiCd, nickel-metal hydride, lithium-ion, Li-ion polymer, and, less commonly, zinc-air and molten salt batteries. The major concerns with these batteries which tend to restrict the growth of BEV are:

  • Rechargeable batteries are usually the most expensive component of BEV, being about half the retail cost of the car. Cheaper, new technology batteries are required to manufacture cheaper cars and reach cost parity with similar IC engine driven cars.
  • Compared to liquid fuels, most current battery technologies have much lower specific energy (energy per unit mass), this often impacts the maximum range of the vehicles. Consequently, this gives rise to what is known as  ‘range anxiety’, the drivers’ fear of the batteries running out of energy before reaching their destination due to the limited range of existing electric cars.
  • Battery service life should be considered for life cycle costing as all batteries eventually wear out and must be replaced. The rate at which they expire depends on various factors.

This is where graphene fits in beautifully. Now, extensive research is being done in some leading laboratories of the world on the design and application of graphene-based batteries. For instance, a research team from the Lawrence Berkeley National Laboratory is developing a 300-mile electric vehicle battery using a new material called sulfur-graphene oxide (S-GO).  S-GO is a nano-composite material in the form of small particles of sulfur-coated graphene flakes that is designed for use as the cathode in a lithium/sulfur battery.

Lithium/sulfur batteries with S-GO cathodes can revolutionize BEV application. They can store four times more energy than current lithium-ion batteries per unit of weight (600 to 800 Wh/kg), they could extend the range of an electric vehicle to that of a gasoline-powered car—480 to 640 kilometres on a single charge. This is commonly known as ‘Range Parity’.  Sulfur is inexpensive, less than Rs. 70/kg, and Li/S batteries would be significantly lower in cost than Li-ion batteries, creating the potential for rapid and high market penetration.

The physical properties of graphene make it an excellent choice for another electrical device – a supercapacitor. Conventional super-capacitors have the exceptional property to quickly charge and then discharge the energy just as fast. This capability can very much be used for features like ‘regenerative breaking’ or energy recovery from braking, short-term energy storage and burst-mode power delivery. But these conventional supercapacitors cannot replace EV batteries for the very reason that, comparatively, they cannot store the required energy.

Now, here’s the good news. S. Kannappan at the Gwangju Institute of Science and Technology in Korea and others claim that they have a solution. They have built high-performance supercapacitors out of graphene that store almost as much energy as a lithium-ion battery. Whereas, these can charge and discharge in seconds and maintain all this over many tens of thousands of charging cycles. Presently, these are in the experimental stage.

If both these graphene-based technologies – batteries and supercapacitors, are technologically proven and acceptable, it is possible that there may be a race for technological supremacy and dominance in market share. This has happened over and over again in history. One can recall the legendary ‘War of Currents’ between Thomas Edison and George Westinghouse-Nikola Tesla in late 1880  for establishing the supremacy of direct current against the alternating current as the accepted platform for power generation and T&D. More recently, we have witnessed a similar ‘war’ between CDMA and GSM technologies in mobile phone applications. Nevertheless, we may even see a hybrid system where both technologies may co-exist. The battery is to be used for steady conditions whereas the super-capacitor will cater to ‘peaking’ conditions like acceleration or regenerative braking where power ‘bursts’ will be required.

Solar Cells

Direct application of solar cells in BEVs (commonly known as solar vehicles or SEVs), that is, mounting of PV panels directly on the vehicles,  doesn’t seem to be of much promise as of now. The reasons are:

  • Power density: Power from a solar array is limited by the size of the vehicle and the area that can be exposed to sunlight.
  • Cost: Although Costs for solar panels are steadily declining (22% cost reduction per doubling of production volume), these are still costly.
  • Design considerations: It looks to be the main consideration. The lifetime of a solar module is approximately 30 years. This is more than the expected life of the associated vehicle. But the issue is that the present PV panels available in the market are mostly designed for stationary installations. However, to be successful in SEVs, PV panels need to be designed to withstand vibrations. Also, solar panels along with glass add weight.

But solar cells can definitely be used indirectly, being connected to the grid which in turn shall charge the batteries of BEVs through wall sockets.

Now, what is the promise of graphene in solar PV applications?  Presently, as far as my knowledge goes, non-graphene based solar cells with a conversion efficiency of just under 40% are being manufactured and marketed. The established graphene solar cells have an efficiency of up to 2.9%. This is well short of efficiencies we see in another type of conventional solar cells. The good news is, doping graphene with TFSA  has enabled researchers at the University of Florida to set a new efficiency record of 8.6 % for graphene solar cells. The development provides hope for cheaper, durable graphene solar cells in the future. The researchers believe that, if production costs are kept down, graphene solar cells could be a viable contender in the marketplace if they were to reach even 10 per cent power conversion efficiency.

The chassis and body

As mentioned earlier, graphene is one of the stiffest, most lightweight materials on earth. It can easily be mixed with epoxy to obtain plastic-like material that could be used to replace metals within the automotive industry. Now, we can very see strong but lightweight cars made out of graphene. And yes, even the tyres and windscreen too!

Well, this is the extent to which I can visualize. There may be many more uses of this material for vehicle application. In fact, if we consider the broader horizon, The potential uses of this wonder material don’t even scratch the surface of the capabilities of graphene.

Could this be a material that could change the way we live? Will there be a time when we will wonder how we ever lived without graphene? One thing is for sure, graphene has arrived with a bang and is here to stay.

PS:

I recently read that scientists are working on a graphene-based paint that, when applied on a surface exposed to sunlight, can produce electricity similarly to solar panels.

And I thought I have imagination!

Arka Chakravarty

arkac113@gmail.com

References (Internet links):

  1. Graphene based Supercapacitors with Improved Specific Capacitance and Fast Charging Time at High Current Density.
  2. 5 Ways Graphene Will Change Gadgets Forever
  3. Bend It, Charge It, Dunk It Graphene, the Material of Tomorrow
  4. Electric car – Wikipedia
  5. Electric Cars – Battery electric vehicle technology
  6. Electric vehicle battery – Wikipedia
  7. Folded paper lithium-ion battery increases energy density by 14 times
  8. Graphene – Wikipedia
  9. Graphene (potential applications) – Wikipedia
  10. Graphene Batteries Technology
  11. Graphene Pushes EV Battery Range To Magic 300 Mile Number
  12. Graphene Supercapacitors Ready for Electric Vehicle Energy Storage, Say Korean Engineers
  13. Irish Scientists Find Cheaper Way of Producing High Quality Graphene
  14. Perovskites the future of solar power?
  15. Scientists makes graphene breakthrough
  16. Sulfur-graphene oxide material for lithium-sulfur battery cathodes
  17. Supercapacitor – Wikipedia
  18. The Price Of Graphene
  19. War of Currents – Wikipedia
  20. Boeing to mass-produce record-breaking 39.2 percent efficiency solar cell
  21. Doping leads to new efficiency record for graphene solar cells
  22. Graphene-based solar cell hits record 15.6 percent efficiency
  23. Solar panel – Wikipedia
  24. Solar vehicle – Wikipedia
  25. 9 Incredible Uses for Graphene
  26. Graphene Applications & Uses
  27. Graphene Applications and Uses
  28. Graphene Valley Top 5 uses of Graphene that could change the world
  29. ‘Miracle material’ graphene one step closer to commercial use

Leave a Reply

Your email address will not be published.


The reCAPTCHA verification period has expired. Please reload the page.