Improved Initial Charging Capacity of Na-poor Na0.44MnO2via Chemical Presodiation Strategy for Low-cost Sodium-ion Batteries

Sodium-ion batteries(SIBs) are promising for grid-scale energy storage applications due to the natural abundance and low cost of sodium. Among various Na insertion cathode materials, Na0.44MnO2 has attracted the most attention because of its cost effectiveness and structural stability. However, the low initial charge capacity for Na-poor Na0.44MnO2 hinders its practical applications. Herein, we developed a facile chemical presodiated method using sodiated biphenly to transform Na-poor Na0.44MnO2 into Na-rich Na0.66MnO2. After presodiation, the initial charge capacity of Na0.44MnO2 is greatly enhanced from 56.5 mA center dot h/g to 115.7 mA center dot h/g at 0.1 C(1 C=121 mA/g) and the excellent cycling stability(the capacity retention of 94.1% over 200 cycles at 2 C) is achieved. This presodiation strategy would open a new avenue for promoting the practical applications of Na-poor cathode materials in sodium-ion batteries.

Automated summary

Sodium-ion batteries are considered promising for grid-scale energy storage applications due to the abundance and low cost of sodium. The Na0.44MnO2 cathode material, known for its cost effectiveness and structural stability, can be greatly enhanced through a presodiation process, leading to improved initial charge capacity and excellent cycling stability. This presodiation strategy opens up new possibilities for the practical applications of low-sodium cathode materials in sodium-ion batteries.