Cellulose-Hydrogel-Derived Self-Activated Carbon/SnO₂ Nanocomposites for High-Performance Lithium Storage

Alloying negative electrodes possessing higher capacity and rate performance stand at the leading edge of pursuing faster and highly reversible lithium storage. However, the commercialization of alloying materials for lithium ion batteries (LIBs) is still limited by unmanageable volume expansion, causing rapid capacity decay and complex production processes that are difficult to scale up. Here we report a tin dioxide/carbon (SnO2/C) nanocomposite negative electrode with high rate capacity and cycle performance produced by a simple, energy-saving, and high-yield preparation technology. By a tailored air sintering atmosphere and low sintering temperature of 300 °C, the specially designed SnO2/C nanocomposite with porous carbon layer and oxygen-rich functional group was prepared successfully. The electrochemical tests exhibit enhanced capacities of 1074 mAh/g at 0.1 A/g and 459 mAh/g at 12.8 A/g, retaining 656 mAh/g at 1 A/g after 400 cycles. The following full battery testing at the voltage of 4.3 V also demonstrates its practicality. Considering the cost effectivity and resource sustainability, this work may give some inspiration for the next-generation high-performance LIBs.