A dendrite-free Ga-In-Sn-Zn solid-liquid composite anode for rechargeable zinc batteries

Rechargeable zinc batteries (RZBs) have been considered as promising candidates for next-generation large-scale energy storage systems due to the high theoretical capacity (820 mAh g−1), environmental friendliness and sustainability of zinc metal anode. Nevertheless, the practical realization of secondary zinc batteries were impeded by the dendrite issues and consequent poor cycle stability. Here, the Ga-In-Sn-Zn solid-liquid composite (SLC) was proposed to construct SLC-2 electrode by a facile and easily scalable painting strategy. The experimental results and theoretical calculations validated that the solid phase InSn4 in the designed electrode shows good adsorbing ability and lower migration energy barrier of Zn ions, and the electrochemically inert Ga-In liquid component can release the stress changes of the composite electrode, realizing a smooth and dendrite-free Zn deposition. The SLC-2 anode having a areal capacity of 1 mAh cm−2 with excellent stability for 600 h at a current density of 3 mA cm−2 was demonstrated in a symmetric cell, and the SLC-2/PANI battery delivered a reversible capacity of 61.2 mAh g − 1 after 3000 cycles at 1A g − 1. The printing strategy for SLC electrode may open up a new way to obtain highly stable and dendrite-free zinc metal anodes.