article · Nature Communications
Lithium-rich layered oxides are promising materials for positive electrodes in rechargeable lithium batteries because their oxygen redox activity delivers higher capacity than standard transition metal reactions. However, these materials typically suffer from voltage decay during prolonged cycling. Formulations with high nickel content improve voltage stability, but they exhibit poor discharge capacity. Through physicochemical and electrochemical analysis, the relationship between oxygen redox behaviour and specific atomic arrangements within the transition metal layer was examined. Specifically, the balance between LiMn6 and nickel-stabilised LiNiMn5 superstructure units dictates performance. An excess of LiNiMn5 units restricts the insertion and extraction of lithium ions in coin cells, leading to incomplete oxygen redox reactions near 3.3 volts. Adjusting the lithium content allows these superstructure units to be engineered, yielding an optimised material with fewer LiNiMn5 units and significantly improved oxygen redox reversibility.
Next-generation electronics and electric vehicles require rechargeable batteries that can store more energy without degrading rapidly over time. Lithium-rich electrode materials offer substantial energy storage gains, but their practical adoption has been hindered by voltage and capacity loss. Pinpointing the microscopic structures responsible for these issues provides clearer design rules for engineering longer-lasting, higher-capacity battery components.
This work is early-stage materials research tested at laboratory scale in lithium metal coin cells. The findings could inform battery material manufacturers and chemical synthesizers seeking to refine positive electrode formulations for secondary lithium batteries. Commercial application remains distant, as the approach requires further development, cell-level testing, and scale-up before integration into commercial battery production processes can occur.
AI-generated from the published abstract. Always read the original work before citing.
The high-voltage oxygen redox activity of Li-rich layered oxides enables additional capacity beyond conventional transition metal (TM) redox contributions and drives the development of positive electrode active materials in secondary Li-based batteries. However, Li-rich layered oxides often face voltage decay during battery operation. In particular, although Li-rich positive electrode active materials with a high nickel content demonstrate improved voltage stability, they suffer from poor discharge capacity. Here, via physicochemical and electrochemical measurements, we investigate the correlation between oxygen redox activity and superstructure units in Li-rich layered oxides, specifically the fractions of LiMn<sub>6</sub> and Ni<sup>4+</sup>-stabilized LiNiMn<sub>5</sub> within the TM layer. We prove that an excess of LiNiMn<sub>5</sub> hinders the extraction/insertion of lithium ions during Li metal coin cell charging/discharging, resulting in incomplete oxygen redox activity at a cell potential of about 3.3 V. We also demonstrate that lithium content adjustment could be a beneficial approach to tailor the superstructure units. Indeed, we report an improved oxygen redox reversibility for an optimized Li-rich layered oxide with fewer LiNiMn<sub>5</sub> units.
This page summarises published work. The authoritative version sits with the publisher.
DOI: 10.1038/s41467-024-54312-z
Is something wrong with this record? Report it or request removal.
Discussion
Have you built on this work, tried to replicate it, or seen it applied in practice? Share what you know. Verified researchers and MARATTO™ domain experts can open a discussion, and any member can reply. Contributions are reviewed before they appear.
No discussion yet. Open the first thread.
New to MARATTO™? Create a free account.
