Affordable but high-capacity batteries are becoming a thing of the present, and not the future anymore, as manufacturers strive to make battery technology better.
Meanwhile, electric automobile manufacturer Tesla is looking even farther into the future, where expensive batteries are made affordable with silicon. Their new 90 kilowatt-hour battery pack, which includes silicon in the design, is an upgrade for their existing models that increases energy capacity by 5% and vehicle range by 15%.
According to CEO Elon Musk, the company sees the inclusion of silicon in the lithium-ion battery pack, only partially used in the anode, as a baby step toward using more and more silicon in their battery technology.
Batteries have three parts, two electrodes called the anode (-) and the cathode (+). Ions pass between an electrolyte that sits between the two nodes. While current batteries including those made by Tesla use graphite for the anode, silicon anodes of the same size are capable of storing 10 times more lithium ions.
Lower quality silicon is also fine to use in batteries, as opposed to the silicon used in solar cells. That further reduces the costs of manufacturing batteries with silicon.
The reason this technology has not been available either is that it is harder to get the silicon atoms to fit into the anodes than it is to get graphite atoms to fit into the same space. Constant expanding and shrinking from charge-discharge cycles causes the protective film on the silicon to degrade over time, possibly effect lifespan. The problems are difficult to overcome.
Most are working as fast as they can to make to use silicon to make more affordable products. While the industry standard is 1-3% silicon, Tesla may have beaten the industry standard, according to Sam Jaffe, analyst and CEO of Cygnus Energy Storage. He believes that since Tesla credits silicon with the energy storage increase of their new battery upgrade, they may have figured out how to put more silicon into their anodes.
