Stabilized Solid–Solid Interface for Solid-State Sodium Batteries Using Gradient Ion-Electron Conductive Phases Modified Sodium Metal Anode
Yujie Yang, Ge Chang, Zheng Liu, Xingzhu Chen, Xingzhu Chen, Cong Huang, Yang Qian, Zhixiao Liu, Qunli Tang, Aiguo Patrick Hu, Xiaohua Chen, Xiaohua Chen
Abstract
The application of sodium anodes is essential for developing high-energy density, low-cost, and high-security solid-state sodium–metal batteries (SSSMBs) to replace commercial lithium ion batteries. However, poor interface contact, high resistance, and dendrite growth between the sodium anode and solid-state electrolyte (SSE) have hampered the application of SSSMBs. Herein, an ultrastable composite sodium anode with gradient ion-electron conductive phases was constructed through the in situ conversion and alloying reaction between SbF 3 and sodium. The tightly contacted solid–solid interface between the composite anode and sodium superionic conductor oxide SSE is enriched with NaF and inside the anode is enriched with Na 3 Sb, which can inhibit the growth of sodium dendrites and accelerate the transport of bulk-phase sodium to the interface. Benefiting from these advantages, both symmetric and full cells assembled with such composite electrodes display excellent electrochemical performance. These results offer a novel composite anode design for the practical application of SSSMBs.