CuSbS2 as a negative electrode material for sodium ion batteries
Abstract
CuSbS2 was tested as a negative electrode material for sodium-ion batteries. The material synthesized by ball milling offers a specific charge of 730 mAh g-1, close to the theoretical value (751 mAh g-1), over a few cycles. The reaction mechanism was investigated by means of operando X-ray diffraction, 121Sb Mössbauer spectroscopy, and Cu K-edge X-ray absorption spectroscopy. These studies reveal a sodiation mechanism that involves an original conversion reaction in two steps, through the formation of a ternary phase, CuSb(1-x)S(2-y), as well as a NaxS alloy and Sb, followed by an alloying reaction involving the previously formed Sb. The desodiation process ends with the reformation of the ternary phase, CuSb(1-x‧)S(2-y‧), deficient in Sb and S; this phase is responsible for the good reversibility observed upon cycling.
- Publication:
-
Journal of Power Sources
- Pub Date:
- February 2017
- DOI:
- 10.1016/j.jpowsour.2016.12.100
- Bibcode:
- 2017JPS...342..616M
- Keywords:
-
- Negative electrode;
- Na-ion battery;
- Ternary phase;
- Conversion material