UC San Diego researchers create solid-state battery that could stir up the power industry

A team of UC San Diego engineers have been working on an all-solid-state battery that combines a solid electrolyte and a silicon anode. The combination of these components significantly increases power density, improving battery life and charging time.

The study published by UC San Diego explains how this new type of solid-state battery may revolutionize certain areas of the power industry through the benefits it brings. Besides charging faster and lasting longer, this all-solid-state battery composition doesn’t include flammable substances, toxic or volatile compounds, nor rare elements, making it a safer than most other batteries.

Instead of using graphite anodes like most other battery technologies, the UC San Diego-developed battery uses a silicon anode. This change alone allows the battery to increase its power density by up to 10x, but it raises the issue of expansion and contraction as the battery is charged and depleted.

To solve this issue, researchers started by removing the carbon and binders commonly used in all-silicon anodes. Moreover, they opted for a micro-silicon anode instead of a nano-silicon one, choosing a less processed and cheaper solution. Lastly, they replaced the liquid electrolyte with a sulfide-based solid electrolyte to increase the anode’s stability.

“The solid-state silicon approach overcomes many limitations in conventional batteries. It presents exciting opportunities for us to meet market demands for higher volumetric energy, lowered costs, and safer batteries especially for grid energy storage,” said Darren H. S. Tan.

The current all-solid-state battery prototype already shows some promise. It is capable of delivering 500x charge and discharge cycles while retaining 80 percent of its capacity at room temperature, but the technology should improve as it keeps being developed.

At the moment, the new battery technology is licensed to Unigrid, a startup company formed by Darren H. S. Tan, who’s also leading the battery’s project. LG Energy Solutions is also collaborating on this research through its open innovation program.

Car manufacturers like BMW, Toyota and VW, among others, are developing solid-state battery tech for their products, but they aren’t the only ones. Other companies like Qing Tao Energy Development Co and Sakuu are also working on solid-state batteries.

We have yet to see a product powered by this type of battery, but considering the latest developments, it shouldn’t take long.