摘要
Ordered layered honeycomb structures are crucial for the unique redox mechanism in Co-free Li-rich oxide materials(LMNO).However,oxygen release and irreversible cation migration originating from this distinctive structure during cycling have hindered the further commercialization of LMNO.Herein,we report a strategy to modulate the nanoscale atomic arrangement and electronic band structures by deliberately introducing an integrated short-range disorder in the Li-rich structure with Ce/F dual-doping(denoted as LMNO-CFSD).This work explicitly reveals the induction of this disordered structure and comprehensively investigates its effects on the lattice stability.As a result,the LMNO-CFSD cathode exhibits a high energy density of 934.8 Wh kg_(cathode)^(-1),and achieves a remarkable lifespan of 800 cycles with 70.1%capacity retention at 1 C in LMNO-CFSD||graphite full cells.Spectroscopic studies corroborated by first-principles calculations reveal that this integrated short-range disorder with dual-doping effectively modulates the formation energy of oxygen vacancies.It also tailors the crystal and anionic band structure in the Li-rich phase,fundamentally mitigating detrimental oxygen release and transition metal migration during Li^(+)(de)intercalation.Our findings illuminate the crucial role of correlated disorder in enhancing the electrochemical properties of Li-rich layered oxides,thereby offering new design principles for high-performance cathode materials in next-generation lithium batteries.
基金
supported by the National Natural Science Foundation of China(NSFC,52090034)
the National Key R&D Program of China(2020YFA0711500)。
