Layered manganese phosphorus trisulfides for high-performance lithium-ion batteries and the storage mechanism

Although advanced anode materials for the lithium-ion battery have been investigated for decades, a reliable, high-capacity, and durable material that can enable a fast charge remains elusive. Herein, we report that a metal phosphorous trichalcogenide of MnPS3 (manganese phosphorus trisulfide), endowed with a unique and layered van der Waals structure, is highly beneficial for the fast insertion/extraction of alkali metal ions and can facilitate changes in the buffer volume during cycles with robust structural stability. The few-layered MnPS3 anodes displayed the desirable specific capacity and excellent rate chargeability owing to their good electronic and ionic conductivities. When assembled as a half-cell lithium-ion battery, a high reversible capacity of 380 mA h g(-1) was maintained by the MnPS3 after 3000 cycles at a high current density of 4 A g(-1), with a capacity retention of close to or above 100%. In full-cell testing, a reversible capacity of 450 mA h g(-1) after 200 cycles was maintained as well. The results of in-situ TEM revealed that MnPS3 nanoflakes maintained a high structural integrity without exhibiting any pulverization after undergoing large volumetric expansion for the insertion of a large number of lithium ions. Their kinetics of lithium-ion diffusion, stable structure, and high pseudocapacitance contributed to their comprehensive performance, for example, a high specific capacity, rapid charge-discharge, and long cyclability. MnPS3 is thus an efficient anode for the next generation of batteries with a fast charge/discharge capability.