Nitrogen-doped carbon nanosheet coated multilayer graphite as stabilized anode material of potassium-ion batteries with high performances

• Published in: Electrochimica acta Vol. 380; p. 138254
• Main Authors: Tian, Sheng, Zhang, Ying, Yang, Chenghao, Tie, Shaolong, Nan, Junmin
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.06.2021; Elsevier BV
• Subjects: Anode material; Anodes; Carbon; Electrochemical performance; Electrode materials; Graphite; Multilayers; Nanosheets; Nitrogen; Nitrogen-doped carbon nanosheet coating; Potassium; Potassium-ion batteries; Rechargeable batteries; Anode material; Electrochemical performance; Nitrogen-doped carbon nanosheet coating; Potassium-ion batteries
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2021.138254

By designing a multi-functional layer on the graphite surface, nitrogen-doped carbon nanosheet (NC) coated multilayer graphite (NC@MG) is synthesized as a promising anode material of potassium ion batteries (KIBs) with enhanced performances. Compared with the conventional graphite and multilayer graphite (MG), NC@MG exhibits a comparative flat discharge platform voltage of graphite anode and enhanced cyclic stability, rate performance, and specific capacity. It is indicated that the modified NC coating facilitates the formation of a stable SEI film on the NC@MG surface, which not only helps to improve the cycle stability, but also maximizes the embedding of K+ into the MG. The nitrogen elements in the NC also increase the electronic conductivity, which is beneficial to the rate performances of NC@MG. After 200 cycles at a current density of 50 mA g−1, the specific capacity of NC@MG is 252.7 mAh g−1; after 1000 cycles at 200 mA g−1, the specific capacity is still 215.7 mAh g−1. This work can not only obtain a stabilized graphite-based anode material of KIBs with enhanced electrochemical performances to date, but also provide a routine to modify and utilize the commercial graphite materials for KIBs. [Display omitted]