Fast-Charging Lithium–Sulfur Batteries Enabled via Lean Binder Content

Next-generation energy storage devices such as lithium–sulfur batteries (LSBs) face several challenges including fast charging and high-power delivery. Thus, it is necessary to improve the stability of the electrodes with efficient electrochemical system. In this work, a durable sulfur cathode even at high rates is enabled via lean binder content. The binder consists of a chitosan cross-linked with a carboxylated nitrile–butadiene rubber (XNBR), which exhibits high affinity toward lithium polysulfide along with robust mechanical properties because of the synergistic effect of the polar chitosan and the elastomeric XNBR. Despite using extremely small content of binder (3 wt%), the LSB shows a highly stable long-term cycling performance with capacity retention decay values of 0.026% and 0.029% after 500 cycles at 5 and 10 C. Moreover, the cell shows an outstanding specific capacity of 228 mAh g⁻¹ at an ultrahigh charge–discharge rate of 20 C. This approach may significantly improve the design of the sulfur cathode and pave a facile way to fabricate commercially viable next-generation energy storage devices.