Diamonds could improve battery safety and storage levels

Tiny diamonds could improve battery safety and energy capacity by preventing short-circuits.

An international team of researchers from Drexel University in the US and Chinese establishments Tsinghua University and Huazhong University of Science and Technology collaborated to improve the safety of lithium-ion batteries, which power many mobile devices, from phones to laptops.

Despite widespread use, the batteries are prone to meltdowns and fires because of short-circuiting. The malfunctions are often caused by dendrites, tiny tendril-like formations that build up over time and force through electrode separators, connecting the two sides and igniting highly-flammable electrolyte solutions.

The team mixed nano-diamonds – tiny particles 10,000 times smaller than the width of human hair but with the same structure as larger diamonds – into the solution. The particles formed a smooth surface in the batteries, stopping hazardous dendrites from forming and preventing short-circuits.

The process could help improve energy storage, said the researchers. Current battery designs use electrodes made of graphite filled with lithium, which prevents dendrites but reduces capacity by about 10 times. The new process could improve storage by allowing the use of pure lithium.

The researchers, led by engineer Yury Gogotsi of Drexel University, said their nano-diamond-infused batteries are stable over charge-discharge cycles of 200 hours – long enough for some industrial or military uses but not yet adequate for laptops or phones.

The research was featured in Nature Communications. 

This article appears in the September print issue of PE.