Li7La3Zr2O12 coated LiNi0.87Co0.05Mn0.05Al0.03O2 for lithium-ion cells with enhanced performance

The Ni-rich layered cathodes have demonstrated the great advantage on pushing the limit of lithium-ion batteries to higher energy density but suffer from the poor cycling performance and unstable safety reliability. Surface covering is a practical and effective strategy to ameliorate the drawbacks. In the work, the Li7La3Zr2O12 widely used in solid electrolyte owing to the high Li+ conductivity is applied to cover on the surface of LiNi0.87Co0.05Mn0.05Al0.03O2 to enhance its electrochemical properties and thermal stability, which are confirmed by the X-ray diffraction, scanning electron microscope, energy disperse spectroscope, transmission electron microscope, X-ray photoelectron spectroscope, differential scanning calorimetry and charge-discharge tests. As a consequence, the Li7La3Zr2O12 coated cathodes demonstrate the significant promotion on high rate capability, discharge capacity at high and low temperature, long cycling stability and safety performance. Such a big elevation could be attributed that the Li7La3Zr2O12 coating strategy effectively protects the cathode particles against the electrolyte attack, maintains the particles morphology integrality during cycling and enhances the thermal stability of pristine cathode.