Mesoporous carbon/silicon composite anodes with enhanced performance for lithium-ion batteries

Abstract

Silicon offers the highest theoretical capacity among all anode materials investigated for Li-ion batteries, making it a promising alternative anode to the currently used graphite. However, Si anodes still face significant challenges for commercialization because of the poor cycling performance induced by the huge volume change (300%) that occurs during the insertion/extraction of lithium ions. In this paper, we report a mesoporous C/Si composite synthesized by an organic–organic self-assembly of a triblock copolymer and a resorcinol–formaldehyde resin. Large number of hydroxyl groups of the RF resin directs the formation of a mesostructure and coating/dispersion of the Si nanoparticles by strong hydrogen bonding interactions. The mesoporous carbon matrix efficiently accommodates the volume change of nano-Si and maintains the integrity of the nano-Si electrodes. Significant improvement in the electrochemical performance was demonstrated in comparison with the bare Si nanoparticle anodes. In addition, the synthesis method can be easily scaled up for mass production.