Graphene-on-silicon boosts Li-ion cell energy density
29 June 2015
Samsung funded research into the use of silicon in next-generation lithium-ion batteries claims to have overcome silicon's inherent problem: deterioration over charge-discharge cycles.
A team of Samsung researchers has achieved direct graphene growth over silicon nanoparticles without silicon carbide formation. Their work - which could see significant improvement in the energy density of Li-ion batteries using silicon anodes - is reported in the journal, Nature Communications. The Nature Communications article states:
"The graphene layers anchored onto the silicon surface accommodate the volume expansion of silicon via a sliding process between adjacent graphene layers.
"When paired with a commercial lithium cobalt oxide cathode, the silicon carbide-free graphene coating allows the full cell to reach volumetric energy densities of 972 and 700Wh/l at first and 200th cycle, respectively, 1.8 and 1.5 times higher than those of current commercial lithium-ion batteries.
"This observation suggests that two-dimensional layered structure of graphene and its silicon carbide-free integration with silicon can serve as a prototype in advancing silicon anodes to commercially viable technology."
Apart from mobile phone users needing to charge their devices less frequently, this development holds promise for longer range electric vehicles. However, the work is at an early stage and the new technology may take a couple more years before it can be incorporated into mobile phones.