Facile In Situ Cross-Linked Robust Three-Dimensional Binder for High-Performance SiO_x Anodes in Lithium-Ion Batteries

Silicon oxide (SiOx, 0 < x < 2) is considered one of the most promising anode materials for next-generation lithium-ion batteries due to its high theoretical capacity. However, its commercial application is limited by the non-negligible volume change during cycling. Herein, a three-dimensional (3D) structure of carboxymethyl cellulose (CMC) cross-linked with iminodiacetic (c-CMC-IDA150) was facilely formed through in situ thermal cross-linking of CMC and iminodiacetic acid (IDA) in the fabrication process of the electrode, which could construct a robust network to restrain the volume change of the SiOx anode and maintain the integrity of the electrode. In addition, the 3D cross-linked c-CMC-IDA150 provides sufficient contact sites to improve the adhesive strength. Thus, SiOx@c-CMC-IDA150 shows a prolonged cycle life, achieving a capacity of 1020 mAh g–1 after 100 cycles at a current density of 0.2 A g–1. With the increase in the current density to 1.0 A g–1, SiOx@c-CMC-IDA150 exhibits a reversible capacity of 899 mAh g–1 after 200 cycles with a capacity retention of 70.2%. This work provides a potential perspective to fabricate high-performance SiOx anodes and promote the stability of high-capacity Si-based anodes.