A mechanically robust and ion-conductive polymeric coating containing two polymers, polyethylene glycol tert-octylphenyl ether and poly(allyl amine), with four tailored functional groups is developed for graphite and graphite-Si composite anodes. The coating, acting as an artificial solid electrolyte interphase, leads to remarkable enhancement in capacity reversibility and cycling stability, as well as a high-rate performance of the studied anodes.

No abstract

A high-performance graphite-Si composite anode for Li-ion batteries containing Si nanoparticles (NPs) attached onto graphite microparticles was synthesized by adopting a polymer-blend of poly(diallyl dimethyl-ammonium chloride) and poly(sodium 4-styrenesulfonate). The polymer-blend enabled uniform distribution of Si NPs during synthesis and served as a robust artificial solid-electrolyte interphase that substantially enhanced the cycle stability and rate performance of the composite electrode. The electrode exhibited a specific capacity of 450 mA h g(-1), 96% capacity retention at a 10 C-rate, 95% retention after 200 cycles, and the same electrode expansion behavior as a pristine graphite electrode.