Stabilization of the surface and lattice structure for LiNi0.83Co0.12Mn0.05O2via B2O3 atomic layer deposition and post-annealing
The Ni-rich LiNixCoyMn1−x−yO2 cathode (x ≥ 0.6) shows weak rate capability due to its deleterious surface lithium impurities and lattice defects. Herein, uniform ultrathin B2O3 coatings built by atomic layer deposition (ALD) are utilized to construct a B3+ doped single-crystal LiNi0.83Co0.12Mn0.05O2 (SC83) via post-annealing. LiOH is consumed due to reacting with B2O3 during the B2O3 ALD process, and then B2O3 is transformed into B3+ doping accompanied by the reduction of Li2CO3 during the post-annealing. Surface and bulk characterization results show that B3+ tends to diffuse into the bulk of the SC83 during the post-annealing, which expands the a and c axes and reduces the Li+/Ni2+ mixing of the SC83. When the B3+ content exceeds 0.54 wt%, B3+ segregation occurs on the surface of the SC83, which decreases the electronic conductivity of the SC83. B3+ doping at the content of 0.54 wt% gives the highest capacity of 177.6 mA h g−1 at 1C rate. The B2O3 ALD coupled with post-annealing builds a highly electronic and Li+ conductive surface and bulk for the SC83, which is the key to the improvement of the rate capability.
危险品化学品经营许可证（带存储）