An amorphous wrapped nanorod LiV3O8electrode with enhanced performance for lithium ion batteries

Abstract

To achieve a good combination of high capacity, cyclability and rate capability in an electrode is still a great challenge for lithium-ion batteries, especially those used for electric vehicles. The present work has developed a simple and effective strategy to solve this problem in the layer structured LiV₃O₈ positive electrode. This has the highest theoretical capacity of the currently available positive electrodes but it has not yet been achieved in practice along with high rate capability. In our approach, an amorphous wrapped [100] orientated nanorod structure has been fabricated in a LiV₃O₈ thin film by adjusting the oxygen partial pressure in the deposition process using radio frequency (RF) magnetron sputtering. With this structure, a record combination of high capacity and superior high-rate capability, namely 388 mA h g⁻¹ at C/5 and 102 mA h g⁻¹ at 40 C, has been achieved along with stable cycle life. The result revealed that the orientated nanorods provide additional ionic transport channels and their amorphous wrapping layer can withstand the anisotropy of the surface during the intercalation of Li ions.