Rapid mechanochemical synthesis of polyanionic cathode with improved electrochemical performance for Na-ion batteries

Xing Shen,Xingguo Qi,Qiangqiang Zhang,Chao Yang,Huizhou Liu,Miao Han,Yong-Sheng Hu,Bo Li,Quan Zhou,Junmei Zhao

doi:10.1038/s41467-021-23132-w

Abstract

Na-ion batteries have been considered promising candidates for stationary energy storage. However, their wide application is hindered by issues such as high cost and insufficient electrochemical performance, particularly for cathode materials. Here, we report a solvent-free mechanochemical protocol for the in-situ fabrication of sodium vanadium fluorophosphates. Benefiting from the nano-crystallization features and extra Na-storage sites achieved in the synthesis process, the as-prepared carbon-coated Na3(VOPO4)2F nanocomposite exhibits capacity of 142 mAh g−1 at 0.1C, higher than its theoretical capacity (130 mAh g−1). Moreover, a scaled synthesis with 2 kg of product was conducted and 26650-prototype cells were demonstrated to proof the electrochemical performance. We expect our findings to mark an important step in the industrial application of sodium vanadium fluorophosphates for Na-ion batteries.

Highlights

Na-ion batteries have been considered promising candidates for stationary energy storage
Mechanochemical synthesis based on high-energy ball milling (HEBM) has made great strides in the rapid preparation of cathode materials with beneficial highperformance properties[32,33,34,35]
In summary, a rapid and simple HEBM solid-state protocol for the fabrication of ultrafine polyanionic nanoparticles is proposed for the first time

Summary

Introduction

Na-ion batteries have been considered promising candidates for stationary energy storage Their wide application is hindered by issues such as high cost and insufficient electrochemical performance, for cathode materials. The high preparation cost and moderate electrochemical performance limit their large-scale industrial production. The synthesis of pure NVPFs based on the high-temperature solid-state method has been widely investigated[20,21,22]. This method undoubtedly increases the cost of an electrochemical storage system, but it often results in impurities due to V and F volatilization during high-temperature processing.

Methods

Results

Conclusion