Accelerating charging and elevating capacity of TiO ₂ by interface space charge storage

Abstract Titanium dioxide (TiO 2 ) is an extremely promising anode material for lithium‐ion batteries due to its low cost, minimal volume change, and extended cycle life. However, its electrochemical performance is severely hindered by inherent issues such as poor ionic and electronic conductivity. Here, we design a dual‐phase conductor Co@TiO 2 , which contributes a synergistic storage mode consisting of a Li‐accepting and an electron‐accepting phase. In situ magnetic characterization and experimental results reveal the space charge storage mechanism in addition to traditional insertion mechanisms. Based on these mechanisms, the specific capacity and rate performance of the Co@TiO 2 electrode have been greatly enhanced. Under a current density of 200 mA·g −1 , the specific capacity of Co@TiO 2 reaches 397.2 mAh·g −1 . Upon increasing the current density to 10 A·g −1 , the electrode still maintains a capacity of 83.1 mAh·g −1 after 900 cycles. This result offers a fresh perspective on the structural design of new anode materials to achieve high energy density.