Facile <i>In Situ</i> Cross-Linked Robust\nThree-Dimensional Binder for High-Performance SiO_<i>x</i> Anodes in Lithium-Ion Batteries

Abstract

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