Enhanced electrochemical performance of LiNi0.6Co0.2Mn0.2O2 cathode for lithium ion batteries via a modified calcination process

Abstract

Nickel (Ni)-rich cathodes with long service life and high energy density are play important role in the rapidly development of lithium ion batteries. However, the rapid development of Ni-rich cathode is still limited by its unstable structure and severely attenuated capacity. Herein, the LiNi0.6Co0.2Mn0.2O2 cathode was obtained from the solid phase method followed by calcination with a low-temperature holding step. The sample (LNCM-3) synthesized with calcination at 250 °C for 6 h and 850 °C for 10 h exhibits higher discharge specific capacity of 194.8 mAh g−1 and 131.0 mAh g−1 at 0.1C and 5C current density, and the capacity retention were 96.2 % and 75.7 % at 1C and 5C after 100 cycles in half cell. The obvious improved electrochemical performances are due to the low-temperature holding step could extend layer spacing and increase the crystalline of materials, which are confirmed by the results of XRD and TEM. Moreover, the full battery assembled with LNCM-3 as the cathode displays a higher specific capacity of 165.8 mAh g−1 at 0.1C and a superior cycling stability of 96.0 % after 100 cycles at 1C rate in the voltage range of 2.7–4.2 V.