Enabling economic and safe anode pre-lithiation with high value-added material production via vacuum thermal reduction†

Abstract

Anode pre-lithiation with metallic lithium exhibits the merits of uniformity, accuracy and high pre-lithiation capacity and is a very effective pathway to compensate for the consumption of lithium during the formation of a solid electrolyte interphase (SEI) and improve the energy density of rechargeable lithium-ion batteries (LIBs). However, the cost and safety issues of metallic lithium in anode pre-lithiation have become the main bottlenecks for its large-scale application in LIBs. Herein, we propose a low-cost and high-safety anode pre-lithiation strategy with in situ production of lithium metal by the vacuum thermal reduction (VTR) reactions between Ti and LiOH. The evolution of lithium and titanium oxides with elevated reaction temperatures is studied. Li₄Ti₅O₁₂ as the upcycling product of the reduction residue can significantly reduce the pre-lithiation cost. Si/C–Li electrodes lithiated by such an anode pre-lithiation strategy are evaluated using the half and full cells. Our findings provide new anode pre-lithiation approaches for potential large-scale application of the next-generation high-energy LIBs.