Homogeneous distributed natural pyrite-derived composite induced by modified graphite as high-performance lithium-ion batteries anode

Abstract

Natural minerals-based energy materials have attracted enormous attention because of the advantages of good materials consistency, high production, environmental friendliness, and low cost. The uniform distribution of grains can effectively inhibit the aggregation of active materials, improving lithium storage performance. In this work, natural graphite is modified by polyvinylpyrrolidone to obtain modified graphite with reduced size and better dispersion. Natural pyrite composite polyvinylpyrrolidone-modified graphite (pyrite/PG) material with uniform particle distribution is obtained by the ball milling process. The subsequent calcination process converts pyrite/PG into Fe_1−xS compounded with polyvinylpyrrolidone-modified graphite (Fe_1−xS/PG). The homogeneous grain distributions of active material can facilitate the faster transfer of electrons and promote the efficient utilization of active materials. The as-prepared Fe_1−xS/PG electrode exhibits a remarkably reversible specific capacity of 613.0 mAh·g⁻¹ at 0.2 A·g⁻¹ after 80 cycles and an excellent rate capability of 523.0 mAh·g⁻¹ at 5 A·g⁻¹. Even at a higher current density of 10 A·g⁻¹, it can deliver a specific capacity of 348.0 mAh·g⁻¹. Moreover, the dominant pseudocapacitance in redox reactions accounts for the impressive rate and cycling stability. This work provides a low-cost and facile method to fabricate natural mineral-based anode materials and apprise readers about the impact of uniform particle distribution on lithium storage performance.