Enhanced capacity retention based silicon nanosheets electrode by CMC coating for lithium-ion batteries

Abstract

Si nanosheets (SiNS) as two dimensional Si nanomaterials are promising candidates for anodes of lithium ion batteries (LIBs) by their large surface area and excellent mechanical durability. In this study, we fabricated polymeric binder (carboxymethyl cellulose, CMC) coated SiNS electrodes using a spin-coating process and characterized the electrochemical properties. The CMS coated SiNS electrodes were homogeneously covered with a CMC polymer layer and showed the improved capacity retention with maintaining over 90% of initial capacity after several cycles. The result of electrochemical impedance spectroscopy indicates that the CMC layer provide the chemical stability of Si surface and suppress the continuous growth of the SEI layer. Furthermore, CMC coated layer on SiNS provide improved mechanical stability that maintains the adhesion of SiNS to the current collector during the discharge-charge cycles. [GRAPHICS] .