Multi-layered MXene V4C3Tx as new low-voltage insertion anode for Na-ion battery applications

作者：Subramanyan, Krishnan; Chen, Sanming; Li, Na; Ma, Tingting; Liu, Yongping^*; Chandrasekaran, Sundaram^*; Aravindan, Vanchiappan^*

来源：Electrochimica Acta, 2023, 437: 141505.

DOI：10.1016/j.electacta.2022.141505

• MXene V4C3Tx
• Anode
• Na-ion battery
• "Glyme" solvent
• Na3V2(PO4)(3)

We report an MXene V4C3Tx new low-voltage insertion anode and a comparison of the electrochemical performance with ester and ether-based electrolytes in half- and full-cell configuration with Na3V2(PO4)(3)@C (NVPC). Though MXene has been explored for Na-ion batteries (SIB), Mn+1XnTx with n = 3 has been hardly explored. Moreover, the ether-based electrolyte has not been used with any MXenes for electrochemical energy storage, especially in the SIB perspective. The initial irreversibility in the carbonate-based half-cell (V4C3Tx-C) is 128 mAh g(-1) more than the tetraglyme-based half-cell (V4C3Tx-T). After 100 cycles, V4C3Tx-T maintains 84 mAh g(-1), while V4C3Tx-C shows only 60 mAh g(-1), which shows the better retention ability in the ether-based system. As for the rate performance, though V4C3Tx-T has a higher capacity in low currents, at higher currents, V4C3Tx-C shows higher values. This showed that the carbonate-based system has diffusion and capacitive-based Na-ion storage, which enabled it to have a high-rate performance. An extensive in-situ impedance study revealed significant formation of the passivation layer in V4C3Tx-C by irreversibly consuming Na-ions, which causes an increased initial Coulombic inefficiency, whereas no such significant SEI layer formation is evident for V4C3Tx-T. Full-cells were assembled with NVPC cathode in tetraglyme and carbonate-based electrolytes. The full-cell with ether electrolyte exhibited enhanced capacity, capacity retention, and rate performance compared to ester-based electrolytes. The full-cell displayed an energy density of similar to 66 and similar to 74 Wh kg(-1) for tetraglyme and ester-based electrolytes, respectively.

• 单位
  桂林理工大学