Fast Potassium‐Ion Conduction in K<sub>3</sub>LnSi<sub>3</sub>O<sub>9</sub> (Ln = Y and Gd) Enabled by P‐Doping Toward Ultrastable Quasi‐Solid‐State Batteries
Abstract
AbstractSolid‐state potassium‐ion batteries are promising options for large‐scale energy storage due to their high safety and abundance of potassium resources. However, solid‐state potassium‐ion batteries are still in their infancy and the reported electrolyte materials are very limited, making the exploration of solid electrolytes with high ionic conductivity and physical/electrochemical stability a major challenge. Here novel triclinic K3LnSi3O9 (Ln = Y and Gd) potassium‐ion solid electrolyte is reported with low activation energy and high stability. A rational vacancy design strategy is adopted to synthesize K3−xGdPxSi3−xO9 and the result of DFT calculation shows that the diffusion pathways of potassium ions on the ac plane exhibit a fish scale‐like network structure. Specifically, the K2.8GdP0.2Si2.8O9 delivers a high ionic conductivity of 2.9 × 10−5 S cm−1 at 25 °C, accompanied by a stable potassium stripping/plating (a long‐life cycle over 2000 h). As a result, the assembled quasi‐solid‐state KC/K2.8GdP0.2Si2.8O9/PB cell achieves a remarkable cycling performance at a high current density of 1 C (500 cycles, 95.9% capacity retention). These results would no doubt boost research for high‐safety and high‐energy‐density solid‐state potassium‐ion batteries.
Article Details
Authors (8)
Shuhong Yi
College of Materials Science and Engineering Hunan Joint International Laboratory of Advanced Materials and Technology of Clean Energy Hunan Province Key Laboratory for Advanced Carbon Materials and Applied Technology Hunan University Changsha 410082 China
Chenlong Gao
School of Materials Science and Engineering Tongji University Shanghai 201804 China
Qingfeng Fu
College of Materials Science and Engineering Hunan Joint International Laboratory of Advanced Materials and Technology for Clean Energy Hunan Province Key Laboratory for Advanced Carbon Materials and Applied Technology Hunan University Changsha 410082 China
Shiru Wu
College of Materials Science and Engineering Hunan Joint International Laboratory of Advanced Materials and Technology for Clean Energy Hunan Province Key Laboratory for Advanced Carbon Materials and Applied Technology Hunan University Changsha 410082 China
Jian‐Fang Wu
College of Materials Science and Engineering Hunan Joint International Laboratory of Advanced Materials and Technology of Clean Energy Hunan Province Key Laboratory for Advanced Carbon Materials and Applied Technology Hunan University Changsha China
Yan Duan
Menghao Yang
Shanghai Key Laboratory for R&D and Application of Metallic Functional Materials, Institute of New Energy for Vehicles, School of Materials Science and Engineering
Jilei Liu
College of Materials Science and Engineering, Hunan Joint International Laboratory of Advanced Materials and Technology of Clean Energy, Hunan Province Key Laboratory for Advanced Carbon Materials and Applied Technology