Promoted kinetics and capacity on the Li₂CuTi₃O₈/C anode by constructing a one dimensional hybrid structure for superior performance lithium ion batteries

Notably, spinel Li₂CuTi₃O₈ with higher theoretical capacity inherits the characteristics of Li₄Ti₅O₁₂, which is a promising anode material for lithium ion batteries with high energy density. However, the reversible migration of Cu²⁺ in Li₂CuTi₃O₈ during the discharge process limits the diffusion of Li⁺, resulting in poor electrochemical performance. Space confinement is a desirable successful strategy to reduce the size of electroactive materials in return for getting improved kinetics and capacity for secondary ion batteries. Here, we develop a strategy by controlling the precursor of Li₂CuTi₃O₈ in the walls of sulfonated polymer nanotubes, and the highly crosslinked copolymer network in the process of pyrolysis caused strong space confinement for the nanoparticles, which effectively prevented the agglomeration of Li₂CuTi₃O₈ during the calcination process. The hybrid porous nanotubes consisting of Li₂CuTi₃O₈ nanoparticles (5-50 nm) embedded in carbon nanotubes exhibit superior performance (402.8 mA h g⁻¹ at 0.2 A g⁻¹, 101 mA h g⁻¹ at 10 A g⁻¹ after 1000 cycles). This work provides a rapid and durable Li₂CuTi₃O₈ electrochemistry, holding great promise in developing a practically viable Li₂CuTi₃O₈ anode and enlightening material engineering in related energy storage and conversion areas.