Na3P interphase reduces Na nucleation energy enabling stable anode-less sodium metal batteries
Haizhao Yang, Haifeng Lv, En Zhou, Xiaohao Ji, Chunnian Chen, Haolei Yu, Zhaowei Sun, Dawei Zhang, Hongchang Jin, Xianghua Kong, Hengxing Ji
Abstract
Sodium metal batteries (SMBs) are rising as viable alternatives to lithium-ion systems due to their superior energy density and sodium's relative abundance. However, SMBs face significant impediments, particularly the exceedingly high negative-to-positive capacity ratios (N/P ratios) which severely encumber energy density and hinder their practical application. Herein, a novel nucleophilic Na 3 P interphase on aluminum foil has been designed to significantly lower the nucleation energy barrier for sodium atom deposition, resulting in a remarkable reduction of nucleation overpotential and efficient mitigation of dendritic growth at high sodium deposition of 5 mA h cm −2 . The interphase promotes stable cycling in anode-less SMB configurations with a low N/P ratio of 1.4 and high cathode mass loading of 11.5 mg cm −2 , and demonstrates a substantial increase in high capacity retention of 92.4% after 500 cycles even under 1 C rate condition. This innovation signifies a promising leap forward in the development of high-energy-density, anode-less SMBs, offering a potential solution to the longstanding issues of cycle stability and energy efficiency.