Researchers at the USC Viterbi School of Engineering, California, have developed a new lithium-ion battery design that could provide superior performance to current batteries on the market.
The battery technology uses porous silicon nanoparticles in place of graphite anodes. In previous attempts to use silicon anodes, the material broke down due to repeated swelling and shrinking through charging and discharging cycles. The team of researchers, led by Professor Chongwu Zhou and including graduate students from USC as well as Zhejiang University in China, experimented with silicon nanowires less than 100 nanometers in diameter and a few microns long to overcome the problem. The pores on the nanowires allow the silicon to expand and contract without breaking. They also bring the added benefit of increasing the surface area of the anode, allowing lithium ions to diffuse through the battery more quickly and improving the battery performance.
As nanowires are difficult to manufacture on large scales, the research team then transferred the technology over to commercially available silicon nanoparticles, etching them with the same pores used on the wires. The nanoparticles function similarly and can be produced in the greater quantities needed to be a commercially viable technology.
Currently the batteries only last for 200 recharge cycles, compared with the 500 cycles of graphite-based anode designs; however, the team expects to be able to develop the design further and increase this lifespan.
The new battery design could potentially be commercially available in just two to three years.
The USC team aims to focus future research on a new high-capacity cathode material that will cooperate well with the silicon nanoparticle anode and create a completely redesigned and enhanced battery technology.