Assembly of multifunctional Li4Ti5O12@Co3O4 heterostructures for high-performance Li-ion half/full batteries

Highlights: • A 0D/2D heterostructure, Co₃O₄ nanocrystals decorated on Li₄Ti₅O₁₂ nanosheets, was synthesized via a self-assembly strategy. • The improved tap density, suppressed gassing behavior, and enhanced hetero-interface effect are achieved in composite. • The LTO NSs@PCO composite electrode delivers high-rate capacities for Li-ion half/full cells. -- Abstract: Spinel Li₄Ti₅O₁₂ has been attracted extensive attention as an ideal high-rate anode for potential high-power lithium ion batteries. It, however, is still subjects to weaknesses including poor conductivity, sluggish Li⁺ diffusion and gassing problem, resulting in unsatisfactory electrochemical performance. Now, a 0D/2D heterostructure, cobalt tetraoxide nanocrystals decorated on Li₄Ti₅O₁₂ nanosheets, was synthesized via a facile self-assembly strategy. Benefiting from hetero-interface effect, suppressed gassing behavior, enhanced tap density and improved redox reaction kinetics, the as-prepared 0D/2D heterostructure shows superior rate capacity of 150 mA h g⁻¹ at 30 C and outstanding cycling stability of retention a capacity of 130 mA h g⁻¹ after 1000 cycles at 20 C when testing as half battery. Furthermore, superior rate properties are also exhibited for the full cell with as-prepared heterostructure anode and commercial LiFePO₄ cathode (capacities of 126 and 110 mA h g⁻¹ at 20 C and 30 C, respectively). The noticeable electrochemical performances indicate their promising application as the advanced anode in high-power energy storage fields. In particular, our work develops a cost-effective and scalable synthesis method and will exert significant impact upon constructing other advanced electrodes for high-power LIBs.