Ahuja Aakash, Akella Sri Harsha, Sengupta Abhinanda, Kumari Pratima, Noked Malachi, Mitra Sagar
Electrochemical Energy Storage Laboratory, Department of Energy Science and Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India.
Department of Chemistry and BINA-BIU Center for Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan, 5290002, Israel.
Small. 2025 Sep;21(38):e05389. doi: 10.1002/smll.202505389. Epub 2025 Aug 5.
High energy cathodes with low environmental impact are critical for the development of next-generation lithium-ion batteries (LIBs). Lithium nickel manganese oxide (LNMO) cathode is a promising cathode candidate due to its high operating potential (≈4.7 V vs Li/Li), energy density (≈650 Wh kg), thermal stability, and cost-effectiveness. However, it suffers from interfacial degradation and processing limitations. This work pioneers the implementation of niobium oxyfluoride as a multifunctional protective coating on LNMO for high-voltage LIBs applications. A conformal, ultrathin NbOF layer (≈5 nm) is precisely engineered via atomic layer deposition, to improve cathode stability. The coating's dual-anion architecture (F and O) and chemically inert Nb state offers improved resistance to hydrofluoric acid-induced corrosion, suppressing transition-metal dissolution, and mitigating capacity degradation. In half-cell configuration, the niobium oxyfluoride coated LNMO (NbOF@LNMO) versus Li/Li achieves >91% capacity retention after 500 cycles. At high temperature (60 °C), the cathode demonstrates 92.8% retention at 0.1 C and 550 Wh kg energy density after 100 cycles. Full-cell comprising the NbOF@LNMO cathode exhibits >94% capacity retention after 100 cycles. Additionally, the NbOF@LNMO cathode exhibits a remarkable resilience under high-humidity environments, underscoring its robust long-term storage capabilities and processability. This approach provides a pathway toward practical LNMO cathodes for high-voltage, stable, and cost effective LIBs.
对环境影响小的高能阴极对于下一代锂离子电池（LIBs）的发展至关重要。锂镍锰氧化物（LNMO）阴极因其高工作电位（相对于Li/Li约为4.7V）、能量密度（约650Wh/kg）、热稳定性和成本效益，是一种很有前景的阴极候选材料。然而，它存在界面降解和加工限制问题。这项工作率先将氟氧化铌作为多功能保护涂层应用于高压LIBs的LNMO上。通过原子层沉积精确设计了一层保形的超薄NbOF层（约5nm），以提高阴极稳定性。该涂层的双阴离子结构（F和O）以及化学惰性的Nb状态提高了对氢氟酸诱导腐蚀的抗性，抑制了过渡金属溶解，并减轻了容量衰减。在半电池配置中，氟氧化铌包覆的LNMO（NbOF@LNMO）相对于Li/Li在500次循环后容量保持率>91%。在高温（60°C）下，阴极在0.1C下循环100次后容量保持率为92.8%，能量密度为550Wh/kg。由NbOF@LNMO阴极组成的全电池在100次循环后容量保持率>94%。此外，NbOF@LNMO阴极在高湿度环境下表现出显著的弹性，突出了其强大的长期存储能力和可加工性。这种方法为实现用于高压、稳定且具有成本效益的LIBs的实用LNMO阴极提供了一条途径。
