A self-healing CuGa2 anode for high-performance Li ion batteries.

The low capacity of traditional graphite (372 mAh g−1) greatly limits its development as electrode material for future applications, and seeking new anode material is becoming extremely urgent in order to meet the increasing demands. In this work, flexible, self-supporting CuGa 2 films are fabricated by simply painting liquid Ga onto commercial Cu films, which can be used as electrodes directly after annealing. When the CuGa 2 films are applied as anodes in lithium ion batteries, higher capacity (more than 630 mAh g−1 at a current density of 200 mA g−1) and better rate performance (463.7 mAh g−1 at 4000 mA g−1) are achieved compared with those with pure Ga electrodes. Meanwhile, the lithiation-delithiation mechanism is detected by in-situ X-ray diffraction, and the alloying-dealloying processes (CuGa 2 + 2 x Li+ + 2 x e− ↔ Cu + 2Li x Ga) can be verified at the first and fourth cycles. The CuGa 2 anode shows excellent self-healing properties during cycling. Image 1 ∙ A simple, maneuverable method was developed to fabricate CuGa 2 films. ∙ The flexible, self-supporting CuGa 2 films can be used as anodes for LIBs directly. ∙ The CuGa 2 anode exhibits excellent electrochemical performance. ∙ The SEM and in-situ XRD verify the self-healing behaviors of the CuGa 2 anode. [ABSTRACT FROM AUTHOR]