EV Battery Charges in Minutes With a Catch

Philip Oakley

---

15th January 2020

EV drivers may soon be able to charge their car in just five minutes, a Californian tech company claims. However, as with everything, there’s a catch.

The silicon-based lithium-ion battery the company, Enevate, from Irvine, California, has developed may swell quicker than a graphite alternative, meaning the energy capacity and battery performance is reduced dramatically over time.

The company has designed a silicon-dominant anode, instead of a graphite anode found in other EV batteries. Silicon can hold more energy compared to graphite, up to 10 times more electrons, which means the battery’s total energy density is higher, up to 20 or 30% higher if Enevate’s claims are to be believed. However, silicon anodes swell quickly when compared to a regular battery, as they absorb more lithium ions when charging than a graphite anode would. Over time, this causes the surface to crack and total energy capacity to drop dramatically. The anode materials use 70% pure silicon, with the other 30% remaining as graphite. For comparison, other battery anodes which use silicon are said to have a ratio of around 10-90% silicon to graphite.

The heavily optimized cell architecture claims to charge an EV battery to 75% in five minutes, as well as having higher energy density, up to 800Wh/L, whereas other EV batteries have energy densities in the 500-600Wh/L range.

Meanwhile, the higher energy density means a car fitted with the technology would go for 240 miles on that five minute charge, compared to current EVs which go for 40 miles on five minutes of charging, Enevate boasts. 

The battery design is the company’s fourth generation of its ‘XFC-Energy’ platform. It is in discussions with multiple major automakers, and plans to have its battery in cars on the road by 2024-2025.