Let’s start with “Extant”. Every Wednesday night on CBS, this TV series returns with a new episode. Apart from the pleasure of watching Halle Berry, the show is compelling due to its combination of adventurous storylines and the use of near-future artificial intelligence technologies. “Extant” is set in an unspecified future with lots of gizmos and gadgets. The most interesting piece of futuristic technology is a robot son who needs his batteries changed every once in a while. Even though “Extant” is a science fiction, I wondered if there is any battery today that could provide the required energy for a robotic son? How long would these batteries last?
The required energy to keep such a robot working is very large because of the millions of sensors and mechanical movement of the robot. The best available batteries today – “Lithium ion batteries (LIB)” – struggle to power an electric car for 300 miles on a 12 hour charge. How do such batteries work and why are they not yet efficient enough?
LIB is the most important member of rechargeable batteries. In such type of batteries, Lithium moves back and forth between two electrodes, called cathode and anode, for charging and discharging. LIBs are common in many consumer electronics and electric cars due to their relatively high energy density (the amount of energy stored in a unit of battery), low hysteresis (after charging and discharging, there is little loss of energy capacity), and a very slow loss of energy when not in used. LIBs consist of a lithium compound as cathode, spherical graphite as anode, and lithium salt as an electrolyte to allow lithium ion movement between the cathode and anode. Increasing the capacity of LIB is dependent upon better materials for cathode and anode. It should be noted that the combination of cathode, anode, and electrolyte is one cell, several connected cells are called a module and multiple modules go together to make up a battery.
Recently, news regarding the proposed Tesla battery Gigafactory has impacted the industries involved in the LIB supply chain, notably natural flake graphite junior miners. A large component of today’s LIBs is graphite and, for the proposed Tesla factory only, more than 300k metric tons/year graphite would be needed.
I find this all to be a little puzzling. The Gigafactory news has resulted in a boost in graphite market, but graphite-based anodes are not at all adequate for the battery performance required for electric vehicles by 2030. By that date, most hybrid electric cars will have been converted to full electric cars running completely on battery power and without any fossil fuel consumption. This point is not at all controversial amongst scientists and engineers working in the field; the only question for them is what material will replace graphite? The replacement material has to radically improve the performance of existing batteries to provide longer run times (a larger storage of energy), faster charge times, all with the smallest possible weight and at the lowest possible added cost. Furthermore, the new batteries need to be long lasting (over 1000 cycles) and thermally stable (should not be over-heated during charging). Graphene is a leading candidate for the replacement material.
There are many studies and technical papers showing how graphene can improve batteries. Its outstanding electrical and thermal conductivity enhances the activity of cathodes and prevents over-heating of the batteries. Recent results by researchers from Lawrence Berkley lab introduced lithium-Sulphur graphene compounds that generated twice the energy capacity of current batteries and are stable over 1500 cycles. Such batteries could enable electric vehicles with a range of more than 500 miles on a single charge, which is what future electric cars need.
Given that it will take a few year for Tesla factory to be operational, I anticipate a maximum of 10 years supply of graphite to electric cars. By 2030, graphene will likely replace natural flake graphite in LIBs although a lot of graphite will be consumed by graphene producers. Newer technologies such as Li-air batteries or supercapacitors could replace LIBs as well.
On a tangent, many graphite junior miners reacted to the Gigafactory news by trying to approach Tesla and secure a supply agreement. It has to be noted that companies such as Tesla are not cell manufacturer; they assemble modules to build a battery and install them in the electric cars. Other companies – such as Panasonic that has an agreement with Tesla to provide them with battery cells – are the manufacturers of cells. Therefore, Panasonic will be the buyer and direct consumer of spherical graphite, not Tesla. Direct discussion with Panasonic looks like a better bet.
The future of energy industry is largely dependent upon improved batteries. Such batteries will change our life drastically. In a matter of few years, gas stations will be replaced by electric car charging stations; typical auto mechanics require new certification to repair electric cars, and most probably we will buy a car battery and car manufacturers give us the rest of the car for free! “Extant” only shows us the future, graphene builds it.
My name is Soroush and I will tell you what you need to know to make money in graphene.
August 12, 2014 (Source: InvestorIntel, by Dr. Soroush Nazarpour)