Abundant nanoscale defects to eliminate voltage decay in Li-rich cathode materials

Abstract

Li-rich layered oxides are promising high energy-density cathode, but will gradually become defective during cycling, thus suffer detrimental voltage decay. For countering these challenges, here we incorporate abundant nanoscale defects into materials’ lattices to construct a bulk-modified Li-rich composites via a direct in-depth chemical de-lithiation. Due to considerable subtle pre-rearrangements, the yielded complex poses certain features as the electrochemically induced hybrids, but turns out to be superior. Involving rebalanced redox activities, it preserves high specific capacities up to 287 mA h g-1 while presents starting working-potentials close to post-cycled values. Most importantly, this defective structure is capable to enhance the electrochemical stability: except good cycling performances concerning capacity, the tricky and intrinsic voltage decay can also be significantly suppressed to only a fraction of initial levels. This concept of pre-constructing nanoscale disordered system is anticipated to inspire more novel designs of composite cathodes and consequently advance the development of rechargeable lithium-ion battery techniques.