Enhance performance of Li1.2Mn0.54Ni0.13Co0.13O2 cathodes via B3+ doping owe to the suppression of spinel phase generates

Abstract

Boron element was doped into the lithium rich layered oxide Li1.2Mn0.54Ni0.13Co0.13O2 (0%-BLMNC) by ball mill spray drying. B3+ was successfully doped to LMNC particles inside the stability of the crystal structure, reduced the voltage capacity attenuation. TEM measurements showed that the (003) crystal plane spacing of Li[Li0.19Mn0.53Ni0.12Co0.12]B0.01O2 (1%-BLMNC) samples increased from 0.47 to 0.476 nm compared with 0%-BLMNC samples, thus increased the lithium layer spacing from 2.691 Å to 2.952 Å. EIS results also indicated that the lithium ion diffusion coefficient raised from 8.62 × 10−18 cm2s−1 to 1.66 × 10−17 cm2s−1. For half-battery, initial discharge specific capacities of 0%-BLMNC and 1%-BLMNC samples were 193.8 mAh g−1 and 176.6 mAh g−1, respectively. Moreover, after 100 cycles, the volume retention rate of 1%-BLMNC samples was 87.1%, while that of unmodified samples was only 62.5%. For full batteries, the capacity retention of 1%-BLMNC samples after 100 cycles was increased by nearly 15% compared with the matrix. Through material failure analysis, it was further verified that boron doped prevented the transfer of transition metal to lithium layer, stabilized the layered structure and inhibited its phase transition to spinel phase.