Preparation of a peony-liked 3-D hydrotalcite and its electrochemical performance as a zinc negative electrode

Urea was selected as precipitant to prepare a special structure of Peony-liked 3D Zinc-Aluminum layered double hydroxides (P-LDH) through hydrothermal method. The as-prepared materials were researched through morphology characterizations and electrochemical measurements. It was found that the 3D structure of P-LDH consisted by individual sheets forming a Peony-type morphology with excellent crystal. Electrochemical measurements revealed that P-LDH exhibited improved performances, such as better cyclic stabilities, smaller impedance, bigger final discharge specific capacity and retention rate, higher utilization of active materials and more rapidly redox reaction. As a result, the prepared material possesses great stabilities in the whole 1000 cycles, 365 mA h g(-1) of the final discharge specific capacity and 96.3% of a retention rate. This improvement was attributed to the unique 3D peony-liked frame, which possesses bigger channels for electrolyte penetrating-diffusing and exposes more surface to provide active sites for charging-discharging. In addition, the formation mechanism of P-LDH is proposed.