Long-cycling lithium-oxygen batteries enabled by tailoring Li nucleation and deposition via lithiophilic oxygen vacancy in Vo-TiO2/Ti3C2Tx composite anodes
Long-cycling lithium-oxygen batteries enabled by tailoring Li nucleation and deposition via lithiophilic oxygen vacancy in Vo-TiO2/Ti3C2Tx composite anodes
Uncontrollable Li dendrite growth and infinite volume fluctuation during durative plating and stripping process gravely hinder the application of metallic Li electrode in lithium-oxygen batteries.Herein,oxygen vacancy-rich TiO2 (Vo-TiO2) nanoparticles (NPs) uniformly dispersing on Ti3C2Tx (Vo-TiO2/Ti3C2Tx) with excellent lithiophilicity feature are presented as effective composite anodes,on which a dense and uni-form Li growth behavior is observed.Based on electrochemical studies,mutiphysics simulation and the-oretical calculation,it is found that Vo-TiO2 coupling with three dimensional (3D) conductive Ti3C2Tx MXene forms highly ordered lithiophilic sites which succeed in guiding Li ions flux and adsorption,thus modulating the uniform Li nucleation and growth.As a result,this composite electrode is capable of pre-serving Li with high areal capacity of~10 mAh cm-2 without the presence of dendrites and large volume expansion.Consequently,the as-prepared Vo-TiO2/Ti3C2Tx@Li anode shows outstanding performance including low voltage hysteresis (~19 mV) and superior durability (over 750 h).When assembling with the Vo-TiO2/Ti3C2Tx@Li anodes,lithium-oxygen batteries also deliver enhanced cycling stability and improved rate performance.This work demonstrates the effectiveness of oxygen vacancies in guiding Li nucleating and plating behavior at initial stage and brings a promising strategy for promoting the development of advanced Li metal-based batteries.
Long-cycling lithium-oxygen batteries enabled by tailoring Li nucleation and deposition via lithiophilic oxygen vacancy in Vo-TiO2/Ti3C2Tx composite anodes