With the growing demand for new energy vehicles and energy storage markets, the cost of commercial lithium-ion battery cathode materials (such as nickel-cobalt-manganese ternary materials and lithium cobalt oxide) has risen sharply over the past decade. In contrast, manganese, with its abundant natural reserves and low cost, offers significant resource advantages. Lithium-rich manganese-based layered oxide cathode materials, which exhibit anion oxygen redox reactions, are considered a transformative approach to breaking the energy density bottleneck of lithium-ion batteries, attracting widespread attention from both industry and academia. However, traditional anion oxygen redox reactions under high voltage (>4.5 V) tend to trigger oxygen-oxygen dimerization, forming peroxide/superoxide intermediate species, leading to irreversible lattice oxygen loss. Additionally, accompanying transition metal (TM) ion migration further induces irreversible phase transitions and lattice damage, resulting in rapid capacity and voltage decay, severely impacting battery lifespan and management. Although various modification strategies, such as bulk doping, surface modification, interlayer stacking sequence regulation, and construction of rock-salt disordered structures, have improved cycling stability to some extent, they remain insufficient in effectively suppressing irreversible lattice oxygen loss and structural degradation during cycling.
Addressing these challenges, Professor Feng Pan’s team from the School of Advanced Materials (SAM) at Peking University Shenzhen Graduate School, leveraging their independently developed materials genomics approach, identified that lattice strain induced by two-phase coexistence is the root cause of structural degradation (Nature, 2022, 606, 305–312). By introducing elastic lattice design, the team successfully developed manganese-based materials with an ultrahigh reversible capacity of >600 mAh g⁻¹ (Adv. Mater., 2022, 34, 2202745); enhanced cycling stability of lithium-rich manganese-based materials through nanoscale phase composite engineering (ACS Energy Lett., 2023, 8, 2, 901–908); mitigated lattice strain via synthetic kinetic control (Energy Environ. Sci., 2024, 17, 3807–3818); and designed a novel lithium-rich manganese-based cathode material with a coherent ordered-disordered structure based on Pauling’s rules (Advanced Materials, DOI: 10.1002/adma.202418580). These studies provide critical theoretical guidance and practical foundations for the design and development of low-cost, high-energy-density lithium-ion battery cathode materials.
Recently, the collaborative team of Professor Feng Pan from Peking University’s SAM, Dr. Tongchao Liu and Khalil Amine from Argonne National Laboratory, and Dr. Mingjian Zhang from The Chinese University of Hong Kong (Shenzhen), based on lithium battery materials genomics, proposed a novel “quasi-ordered” structure design strategy. This strategy constructs a short-range ordered LiMn₆ superstructure with partial Ni substitution in the transition metal layer and introduces a highly cation-disordered structure in the interlayer, effectively achieving highly reversible anion oxygen redox reactions under deep delithiation. The study revealed that the reversibility of lattice oxygen redox reactions is not determined by the degree of oxidation but is closely related to the lattice configuration and oxygen coordination environment. By constructing the “quasi-ordered” structure, the team successfully stabilized oxidized oxygen species in the lattice, significantly suppressing the formation of irreversible O₂²⁻/O₂⁻-like intermediates, greatly enhancing the upper limit of reversible oxygen redox utilization, and achieving high capacity output with “near-zero” voltage decay.
This breakthrough not only provides a new approach to addressing the challenge of lattice oxygen instability but also opens a transformative research pathway for developing anion redox cathode materials with both high energy density and long lifespan. The study, titled “A Quasi-Ordered Mn-Rich Cathode with Highly Reversible Oxygen Anion Redox Chemistry,” was published in the prestigious international journal Journal of the American Chemical Society (JACS) (doi.org/10.1021/jacs.5c03271).
Figure 1. Quasi-Ordered Structure Design for Highly Reversible Anion Redox in Lithium-Rich Manganese-Based Lithium Battery Cathode Materials
Professor Feng Pan from Peking University’s SAM, Dr. Tongchao Liu and Khalil Amine from Argonne National Laboratory, and Dr. Mingjian Zhang from The Chinese University of Hong Kong (Shenzhen) are the co-corresponding authors. Dr. Weiyuan Huang, a doctoral graduate from Peking University’s SAM (now a postdoctoral researcher at Argonne National Laboratory), and master’s graduate Jimin Qiu are the co-first authors. The work was supported by the National Natural Science Foundation of China, the International Joint Research Center for Power Batteries and Materials for Electric Vehicles, the Guangdong Key Laboratory of New Energy Materials Design and Computation, and the Shenzhen Key Laboratory of New Energy Materials Genomics Preparation and Testing.
Link to the paper：https://pubs.acs.org/doi/10.1021/jacs.5c03271
