Chelating-Type\nBinders toward Stable Cycling and High-Safety\nTransition-Metal Sulfide-Based Lithium Batteries

Conversion-type transition-metal sulfides (MS<sub><i>x</i></sub>) are considered promising cathodes due to their\nlow cost,\neasy availability, and high energy density. However, MS<sub><i>x</i></sub> cathodes experience severe capacity decay when cycling\nin conventional carbonate-based electrolytes because of irreversible\nnucleophilic reactions between carbonate solvents and polysulfide\nintermediates. To address this issue, a series of chelating-type binders\nhas been designed for enabling MS<sub><i>x</i></sub> to\nfunction effectively. As a result, a typical transition-metal sulfide\nFeS<sub>2</sub> cathode can work reversibly with a high capacity of\n527.3 mAh g<sup>–1</sup> over 300 cycles, retaining 76.9% capacity\nunder an ultrahigh loading of 5.6 mAh cm<sup>–2</sup>. Additionally,\na new type of battery featuring FeS<sub>2</sub> cathodes coupled with\nLiC<sub>6</sub> anodes in carbonate electrolyte has been developed\nfor high stability (72.0% retention after 300 cycles) and safety.\nThis work demonstrates the potential of conversion-type lithium batteries\nfor achieving long cycle life and high safety.