Stable and efficient lithium storage via Ni ratio and calcination temperatures modulation in Ni–Mn layered cathodes
摘要
Cobalt-free nickel-manganese binary materials are one of the most promising cathode candidates for lithium-ion batteries due to the low reserves, high price, political and ecological unfriendliness of cobalt. The preparation of high-performance Ni–Mn bimetallic materials through controlled synthesis conditions holds significant importance for industrial applications. In this work, through systematic modulation of calcination temperatures and nickel ratios, we have effectively addressed critical challenges in binary layered cathodes, including cationic disordering, detrimental H2–H3 phase transitions, and severe interfacial side reactions. The electrochemical performance and thermal stability tests demonstrate that the medium-nickel cathode calcined at 850 °C (NM64) exhibit superior comprehensive performance, including moderate discharge capacity (181.34 mAh g−1 at 1C), enhanced thermal stability and cycling stability (90% capacity retention after 100 cycles), excellent rate performance (125 mAh g−1 at high rate of 10C). Moreover, a 10 kg sample was prepared further verified its commercial application prospects. The soft-pack battery with commercial graphite anode and NM64-850 cathode achieve a discharge capacity of 171.0 mAh g−1 and retains 86.5% capacity after 180 cycles. The optimized integration of nickel content and calcination temperature endows binary cathodes with balanced electrochemical performance, enabling commercial viability.
Graphical Abstract