CuGaS2 nanoplates: a robust and self-healing anode for Li/Na ion batteries in a wide temperature range of 268–318 K

Abstract

The practical application of batteries in electric vehicles (EVs) and hybrid electric vehicles (HEVs) is hindered by the narrow operating temperature range due to the degradation of the solid–electrolyte interface (SEI) layer at high temperature and poor ion/electron diffusion kinetics at low temperature. Herein, we firstly report CuGaS₂ hexagonal nanoplates as a novel and robust anode material working in a wide temperature range. CuGaS₂ nanoplates with a lateral size of 2–3 μm and thickness of 180–200 nm have been successfully synthesized by a vapor thermal transformation from the oxide counterpart CuGaO₂. The thermal workability of the as-synthesized CuGaS₂ benefits from a synergistic effect including the high conductivity of copper and the self-healing nature of liquid metal gallium. Room temperature CuGaS₂ as a lithium ion battery anode electrode exhibits a high reversible capacity over 521 mA h g⁻¹ after 600 cycles at a high current density of 5 A g⁻¹. Furthermore, as the temperature is lifted to 318 K, the CuGaS₂ electrode exhibits a stable and reversible capacity over 784 mA h g⁻¹ at a high current density of 0.5 A g⁻¹; even at the low temperature of 268 K, a reversible capacity over 407 mA h g⁻¹ can be realized, which is much superior to that of the commercial graphite anode.