Abstract
Lithium-rich layered cathode material(LLM)can meet the requirement of power lithium-ion energy stor-age devices due to the great energy density.However,the de/intercalation of Li+will cause the irre-versible loss of lattice oxygen and trigger transition metal(TM)ions migrate to Li+vacancies,resulting in capacity decay.Here we brought Ti4+in substitution of TM ions in Li12Mn0.54Ni0.13Co0.13O2,which could stabilize structure and expand the layer spacing of LLM.Moreover,optimized Ti-substitution can regulate the anions and cations of LLM,enhance the interaction with lattice oxygen,increase Ni3+and Co3+,and improve Mn4+coordination,improving reversibility of oxygen redox activation,maintaining the stable framework and facilitating the Li+diffusion.Furthermore,we found 5％Ti-substitution sample delivered a high discharge capacity of 244.2 mAh/g at 50mA/g,an improved cycling stability to 87.3％after 100 cycles and enhanced rate performance.Thereby Ti-substitution gives a new pathway to achieve high re-versible cycle retention for LLMs.
维普
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