A facile method to hunt for durable high-rate capability Na0.44MnO2

作者：Ju, Xiaokang; Huang, Hui; Zheng, Hongfei; Deng, Pan; Li, Shengyang; Qu, Baihua^*; Wang, Taihong^*

来源：Journal of Power Sources, 2018, 395: 395-402.

DOI：10.1016/j.jpowsour.2018.05.086

• Na0.44MnO2
• Cathode
• Rate capability
• Cycling stability

Na0.44MnO2 as a potential cathode for sodium-ion batteries (SIBs) has been widely investigated with longer one dimension (1D) morphology. In this work, we propose a facile and effective method to hunt for comprehensive performance of tunnel Na0.44MnO2, especially the rate property. The method is based on a fact that the crystal growth direction and sodium ions intercalation de-intercalation direction are consistent (both along c-axis). Therefore, once the long rod-like cathodes break to two or more shorter 1D Na0.44MnO2, the density of more (001) active planes and short diffusion length are both acquired. In addition, the smashed samples with short nano-bars can still be able to accommodate strain during the cycle process and can be favorable for the contact with electrolyte, which could provide good cycle stability. As a consequence, the materials deliver 90.4 mAh g(-1) discharge capacity at 10C (78% of 0.1C capacity) and maintains 93.91% capacity after 200 cycles at 5C. The sodium-ion chemical diffusion coefficient has been improved with an order of magnitude by galvanostatic intermittent titration technique (GITF) and electrochemical impedance spectroscopy (EIS) test, respectively.

• 出版日期2018-8-15
• 单位厦门大学