California-headquartered Amprius Technologies has revealed a new high-energy density, high-discharge rate silicon anode cell that could potentially be used in aerial and automotive applications. 

The company claims to have achieved a discharge rate of 10C with an energy density of 400 watt-hours per kilogram. The capability could benefit electric vertical take-offs and landings (eVTOL), and the battery can also be installed in unmanned aerial vehicles – all of which require high propulsion power to lift heavy loads. 

A silicon anode, which is the positive electrode in a battery, can store 10 times more lithium than the more commonly used graphite, according to Amprius. The technology enables improved energy density and charging speeds. 

The same capability could extend to high-performance electric vehicles, said the company in a press release. Amprius’ new cell can discharge enough energy to power motors that can accelerate an EV from 0-60 miles per hour in 1.5 seconds. 

I’d take the enthusiast allure of sub-two-second 0-60 mph times with a grain of salt because even the Tesla Model S Plaid, one of the fastest accelerating EVs on the market today, has a claimed 0-60 mph time of 1.9 seconds, excluding rollout distance. 

Amprius also claims that its cell supports high current pulses at a low state of charge (SoC), without dropping under the cut-off voltage. It can reportedly sustain a power density of 3000 watts per kilogram at 30 percent depths-of-discharge, while the maximum power density can exceed 4400 W/kg when the charge is high. 

Several automakers and battery technology companies are attempting to discover breakthroughs to improve energy density and increase driving range. In June 2023, Australia-based Li-S Energy revealed that its third-generation 20-layer cells using semi-solid state lithium-sulfur technology have a volumetric energy density of 540 Wh/l. 

Last year, Chinese battery manufacturer Contemporary Amperex Technology Co. Limited (CATL) revealed that its third-generation nickel-cobalt-manganese (NCM) cell has an energy density of 450 Wh/l. 

While these developments appear promising on paper, we’ll have to wait until experts gauge their real-life performance in applications that the masses can relate to.