Lattice oxygen can play an intriguing role in electrochemical processes, not only maintaining structural stability, but also influencing electron and ion transport properties in high-capacity oxide cathode materials for Li-ion batteries. Here, we report the design of a gas–solid interface reaction to achieve delicate control of oxygen activity through uniformly creating oxygen vacancies without affecting structural integrity of Li-rich layered oxides. Theoretical calculations and experimental characterizations demonstrate that oxygen vacancies provide a favourable ionic diffusion environment in the bulk and significantly suppress gas release from the surface. The target material is achievable in delivering a discharge capacity as high as 301 mAh g^-1 with initial Coulombic efficiency of 93.2%. After 100 cycles, a reversible capacity of 300 mAh g^-1 still remains without any obvious decay in voltage. This study sheds light on the comprehensive design and control of oxygen activity in transition-metal-oxide systems for next-generation Li-ion batteries.

Nature Communications 7, Article number: 12108 doi:10.1038/ncomms12108
Received 10 February 2016 Accepted 01 June 2016 Published 01 July 2016

http://www.nature.com/ncomms/2016/160701/ncomms12108/full/ncomms12108.html