Regulating the Interfacial Performance of All-Solid-State Sodium Batteries Using Lanthanum Substitution in a Na<sub>3</sub>Zr<sub>2</sub>Si<sub>2</sub>PO<sub>12</sub> Solid Electrolyte
Shuaishuai Yang, Jiachen Liang, Jingxin He, Debao Fang, Yu Zhao, Yu Ding, Aining Yin, Yapeng Li, Chengzhi Wang, Jingbo Li, Haibo Jin
Abstract
The main issues currently facing solid-state batteries are the low ionic conductivity of solid electrolytes and high interfacial resistance. By employing a doping strategy to introduce La 3+ into the Na 3 Zr 2 Si 2 PO 12 solid electrolyte increases the ionic conductivity to as high as 1.1 mS cm –1, promotes Na 3 La(PO 4 ) 2 interphase formation, and enhances interfacial charge transfer and cycling stability. The anode interfacial resistance of the Na 3.1 Zr 1.9 La 0.1 Si 2 PO 12 electrolyte decreased to 75 Ω cm 2 at room temperature, merely one-fourth smaller than that of Na 3 Zr 2 Si 2 PO 12 . Moreover, Na 3.1 Zr 1.9 La 0.1 Si 2 PO 12 achieves superior stable sodium plating/stripping cycling over 1800 h, and its performance exceeds that of most reported sodium solid electrolytes. A solid-state Na 3 V 2 (PO 4 ) 3 /Na 3.1 Zr 1.9 La 0.1 Si 2 PO 12 /sodium battery is assembled, demonstrating stable cycling performance with 84.5% capacity retention after 750 cycles. The enhancement of ionic conductivity in the solid electrolyte and the improvement of anode interfacial wettability have facilitated the advancement of solid-state sodium batteries.