▎ 摘　　要

Potassium-ion batteries are emerging as promising candidates for grid energy storage systems because of the abundant potassium resources and high potential. However, the discovery and development of suitable anode materials are far from the demands. Herein, ultrafine carbon-coated MoS2 (MoS2/C) nanosheets encapsulated by a nitrogen-doped graphene network (MoS2/C@NDG) via a simple hydrothermal method are presented. The as-prepared MoS2/C@NDG demonstrates superior rate capability of 176.6 mAh g(-1) at a high current density of 2000 mA g(-1), and still remains 220.7 mAh g(-1) at 1000 mA g(-1) after 150 cycles. The excellent electrochemical performance can be attributed to the dual carbon encapsulated nanostructure and ultrafine 2D MoS2 nanosheet architecture, resulting in enhanced electronic conductivity, fast K+-ion diffusion, and improved pseudocapacitive behavior during the depotassiation and potassiation process. Ex situ XRD and XAFS analysis reveals the K+-storage mechanism with potassium intercalation and conversion reaction, and demonstrates the high reversibility for the local structure of MoS2/C@NDG. This work paves the way for constructing advanced high-performance anode materials of rechargeable PIBs.