Highly Oriented {010} Crystal Plane Induced by Boron in Cobalt-Free Li- and Mn-Rich Layered Oxide.

Abstract

Li- and Mn-rich layered oxide (LMR) materials are a promising candidates for next-generation Li-ion battery (LIB) anode materials because of their high specific capacity. However, their low initial Coulombic efficiency, voltage decay, and irreversible phase transition during cycling are the fatal drawbacks of LMR materials. This work reports on a cobalt-free LMR material composed of primary particles with a boron-induced exposed long- strip-like {010} plane. Because of this unique structure, the long strip-like cathode exhibits excellent electrochemical performance with a discharge capacity of 202 mAh g-1 at 1 C and a retention rate of 95.2% after 200 cycles. In addition, it is found that this long strip-like structure can modulate the redox of oxygen and enhance the reversibility. The irreversible phase transition process from the layered to a spinel and then to a rock-salt phase during cycling is also significantly suppressed. This work provides a feasible method for regulating the exposed {010} plane and a new idea for the structural design of LMR materials.