Si/SiOC/Carbon Lithium‐Ion Battery Negative Electrode with Multiple Buffer Media Derived from Cross‐Linked Dimethacrylate and Poly (dimethyl siloxane)

Abstract

AbstractSilicon holds a great promise for next generation lithium‐ion battery negative electrode. However, drastic volume expansion and huge mechanical stress lead to poor cyclic stability, which has been one of the major drawbacks to prevent its practical applications. In this work, difunctional methacrylate monomers and vinyl terminated poly (dimethyl siloxane) have been cross‐linked via a facile scalable thermal polymerization process, where SiOC (silicon oxycarbide) and carbon network are formed upon calcination. With the multiple buffer media of SiOC and carbon, the electrochemical properties of the Si/SiOC/C (silicon/silicon oxycarbide/carbon) nanohybrid have been effectively improved in terms of both cyclic and rate performance. After one hundred cycles the discharge capacities of Si/SiOC/C composite is also 443 mAhg−1 while the capacity retention is 83.4 %. Through charge and discharge in higher current density, the capacities can also recover to the similar level.