posted on 2023-03-31, 07:03authored byQingdong Tao, Haiyang Ding, Xin Tang, Kaibo Zhang, Jinhan Teng, Haomiao Zhao, Jing Li
Na4Fe3(PO4)2P2O7 (NFPP) is considered to be an ideal cathode
material
for sodium-ion batteries due to its high theoretical capacity, stable
structure, small volume change, low cost, and nontoxicity. However,
the inherent low electronic conductivity of polyanionic materials
limits the application of this material. In this work, we improved
the electronic conductivity and structural stability of the material
through a dual modification synergistic strategy of manganese ion
doping and surface carbon coating and prepared Na4Fe2.9Mn0.1(PO4)2P2O7@C (0.1 Mn-NFPP@C) composites by a simple mechanical-assisted
chemical synthesis method. It can release 119.6 mAh g–1 at 0.1C. The capacity retention rate is 97.4% after 100 cycles at
1C and 84.8% after 3000 cycles at 10C. Many tests and calculations
in this work also show that 0.1 Mn-NFPP@C modified by Mn2+ doping and carbon coating has higher electronic conductivity and
electrochemical kinetics and thus exhibits better electrochemical
performance.