Molybdenum Doping and Lithium Iron Phosphate Coating Stabilize High-Nickel Battery Cathode

High-nickel layered oxides promise some of the highest energy densities available to lithium-ion batteries, but the flagship composition LiNi0.8Co0.1Mn0.1O2, known as NCM811, is limited by rapid capacity fading, interfacial side reactions, and thermal instability. A study published in the journal Ionics on 26 October 2026 by Shuzeng Hou, Ziwen Zhang, Pengpeng Suo, Ning Xie and colleagues reports a two-pronged modification strategy that addresses these weaknesses simultaneously: molybdenum ions introduced into the bulk crystal structure and a LiFePO4-related layer applied to the particle surface.

The bulk component of the strategy relies on Mo6+ doping. Structural characterization and first-principles calculations indicate that the molybdenum ions enlarge the spacing of the lithium slabs in the layered lattice, strengthen local Mo-O interactions, and modify the material’s electronic structure. According to the authors, these changes may contribute to improved lithium-ion transport and greater stability of the host lattice during repeated charging and discharging, when nickel-rich cathodes are prone to structural degradation.

The surface component addresses interfacial behavior. The LiFePO4-related surface-modified sample exhibited lower interfacial resistance and improved interfacial electrochemical behavior, providing a buffer between the reactive nickel-rich bulk and the electrolyte.

The combined treatment produced measurable gains in cycling performance. The optimized composition, designated Mo0.02-NCM811@3LFP, achieved a capacity retention of 90.85 percent after 100 cycles at a 1 C rate, compared with 88.51 percent for the molybdenum-doped material without the surface coating. At a demanding 5 C discharge rate, the fully modified cathode still delivered a discharge capacity of 165.4 mAh per gram, indicating that the dual modification did not sacrifice rate capability.

The thermal results were also substantial. The exothermic onset temperature rose from 184 degrees Celsius for pristine NCM811 to 271 degrees Celsius for the modified material, which the authors present as an indicator of enhanced thermal stability.

The authors frame the work as a demonstration of the potential of combined bulk and interfacial regulation for nickel-rich layered cathodes. The strategy is notable because the two modifications act on distinct aspects of degradation: doping targets the lattice from within, while the phosphate-related coating targets the interface, so the reported benefits appear alongside one another in the same material.

Several caveats apply to the reported numbers. The cycling data cover 100 cycles at 1 C, a relatively short test window for assessing long-term durability. The first-principles calculations support a plausible mechanism for the improved lithium transport and lattice stability, but the authors describe this contribution in cautious terms, noting that the structural changes may contribute to the observed performance rather than proving a definitive causal chain.

Even with those limitations, the study reports that pairing a bulk dopant with a chemically related surface phase improved capacity retention, rate performance and thermal stability in a single nickel-rich cathode, an approach the authors present as relevant to efforts to develop safer, higher-energy lithium-ion cells.

Subject of Research: Combined Mo6+ bulk doping and LiFePO4-related surface modification for improved electrochemical and thermal stability of NCM811 cathodes

Article Title: Combined Mo6+ bulk doping and LiFePO4-related surface modification for improved electrochemical and thermal stability of NCM811 cathode

Article References: Hou, S., Zhang, Z., Suo, P., & Xie, N. (2026). Combined Mo6+ bulk doping and LiFePO4-related surface modification for improved electrochemical and thermal stability of NCM811 cathode. Ionics. https://doi.org/10.1007/s11581-026-07606-9

Image Credits: AI Generated

DOI: 10.1007/s11581-026-07606-9

Keywords: NCM811, cathode materials, lithium-ion batteries, molybdenum doping, LiFePO4 coating, thermal stability, capacity retention, surface modification, first-principles calculations, nickel-rich layered oxides, Combined, bulk