Boosting the lithium storage property of nickel-zinc layered double hydroxides by intercalation with dodecyl sulfate anions

As a promising anode material for lithium-ion batteries (LIBs), nickel hydroxide has attracted much attention due to its high theoretical capacity, easy preparation, and relatively low cost. In this work, dodecyl sulfate anions (DS−) intercalated nickel-zinc layered double hydroxide (Ni-Zn-LDH) is synthesized by hydrothermal method to solve the problems of poor conductivity and significant volume effect of nickel hydroxide. The physical characterization results show that the introduction of DS− in Ni-Zn-LDH can increase the interlayer spacing and form a more open morphology. The electrochemical test results show that Ni-Zn-LDH prepared at n(DS−)/n(Ni2+) of 2:10 (NZDS-20) has the best lithium storage performance. The material exhibits a high specific capacity of 850 mAh g−1 at 0.5 A g−1 over 400 cycles and maintains a specific capacity of 473.5 mA h g−1 at 3 A g−1. GITT analysis demonstrates that the intercalation of DS− efficiently enhances Li+ discursivity and decreases the overpotential of Ni-Zn-LDH during discharge and charge processes. Moreover, NZDS-20 shows a significant pseudocapacitance effect during discharge and charge processes. This work provides an idea and approach for the intercalation modification and performance optimization of LDH-based anode materials for LIBs.