In-situ construction of chemically bonded conductive polymeric network for high-performance silicon microparticle anodes in lithium-ion batteries

The development of high-performance silicon anodes through a simple synthetic process remains unprecedentedly challenging due to poor cycle life caused by huge volume changes, especially for Si micro-particle (SiMP) anodes with a commercial level of Si loading (>1 mg cm−2). Herein, we develop an in-situ method for constructing three-dimensional (3D) conductive polymeric network during electrode preparation, as high-performance SiMP anodes. The 3D conductive polymeric network thus produced is composed of polyacrylic acid (PAA) chemically bonded onto amino-functionalized long singe-wall carbon nanotubes (SCNT–NH2–L). The resultant composite electrode, at a high Si loading of 5.37 mg cm−2, can realize an ultrahigh areal capacity of 10.59 mAh cm−2 and stable cycle performance at 600 mA g−1, which is superior to most of the state-of-the-art representative Si-based anodes. The enhanced electrochemical performance is due to the synergistic effect of conductive network and chemical bonds, which can buffer volume expansion and constrain the pulverized silicon particles to keep the electrical contact. Our work provides a novel but simple strategy to enable stable operation for advanced high-capacity anodes with large volume changes.