Self-assembled Zn-Al-F layered double hydroxides enabling dendrite-free Zn deposition process in high-rate Ni-Zn secondary batteries

The practical utilization of high-rate Zn-based secondary batteries is seriously plagued by the limited cycle stability and undesirable dendrite growth of Zn anodes during repeated charge/discharge process. Herein, we present the design and preparation of Zn-Al-F layered double hydroxides (LHDs) to enable the uniform zincate deposition and inhibit dendrite formation. The dendrite-free deposition of zincate is mainly ascribed to the uniform size distribution, fluorine-intercalated functional interlayer, regulated current density distribution, abundant electrochemical active sites and efficient ion diffusion channel of as-prepared Zn-Al-F LHDs. Furthermore, the potential of Zn-Al-F LHDs is investigated in a Ni-Zn aqueous secondary battery, which renders a high specific capacity of 383.08 mA h g(-1) based on the total mass of Zn-Al-F LHDs and excellent cyclic stability with a capacity retention of 89.03% after 500 cycles at 1 A g(-1). Moreover, at the current density of 100 A g(-1), a peak power density of 168.9 kW kg(-1) and a high energy density of 466.08 W h kg(-1) have been achieved, which are significantly higher than the previously reported LHDs in Ni-Zn batteries.