Controllably elevating the initial Coulombic efficiency of Li3VO4 anode via a facile electrode pre-lithiation technique for lithium-ion batteries

Li 3 VO 4 has been a promising insertion anode material for Li-ion batteries, which has high theoretical capacity (up to ∼600 mAh g −1 ) and safe Li insertion voltage (0.5–1 V vs. Li/Li + ). However, the low initial Coulombic efficiency (ICE) has always been the bottleneck limiting its commercialisation. Here, we propose a facile pre-lithiation method to controllably elevate the ICE by the post-treatment of the prepared Li 3 VO 4 composite electrode based on an immersion reaction. In this process, the whole electrode was immersed in the liquid Li source, via which the ICE of the Li 3 VO 4 electrode can be controllably elevated from 80% to over 100% within 5 min of pre-lithiation. Rather than the traditional powder treatment for pre-lithiation, this process we proposed minimizes the impact of pre-lithiation on the battery assembly process. Moreover, we further investigated the effect of this pre-lithiation process on the functional components in the electrode. For the first time the ICE of Li 3 VO 4 electrode was elevated to 100%. As a result, the initial reversible capacity of LiFePO 4 ∥Li 3 VO 4 full cell was improved from 44.0 to 146.3 mAh g −1 , demonstrating the feasibility and great potential of the process.