Solid lithium electrolyte-Li₄Ti₅O₁₂ composites as anodes of lithium-ion batteries showing high-rate performance

A new concept lithium-ion conducting lithium lanthanum titanate solid electrolyte and Li₄Ti₅O₁₂ composite is proposed as efficient anode of lithium-ion batteries with outstanding rate performance, which can be facilely prepared by one-pot combustion technique. The as-synthesized composites are in micrometer size with dense nature which effectively reduces the electrode-liquid electrolyte interface area, thus decreasing irreversible capacity during the first charge-discharge cycle and prolonging cycling stability. However, the composites are rich in lithium lanthanum titanate and Li₄Ti₅O₁₂ dual phase boundaries due to intimate nanoscale mixing of the two phases. The apparent lithium-ion conductivity of the composite electrode gets significantly improved as compared to pristine Li₄Ti₅O₁₂ due to the incorporation of lithium lanthanum titanate phase, a high lithium ionic conductor. As a result, the as-synthesized composites show a high capacity of 113.5 mA h g^-1 even at a discharge rate of 40 C, more than 200% that of a pristine Li₄Ti₅O₁₂. The concept is general, which may also be applicable to other electrode materials, and it thus introduces a new way for the development of high rate-performance electrodes for lithium-ion batteries.