Tuning Li occupancy and local structures for advanced Co-free Ni-rich positive electrodes.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 40044666.
- Also identified by DOI 10.1038/s41467-025-57063-7 and PMC identifier 11882807.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Structure evolution and surface reactivity have long been regarded as the most crucial points for studying Ni-rich positive electrodes for Li-ion batteries. Unfortunately, the influence of Li occupancy as a single factor on electro-chemomechanical stability has been overlooked and is missing, owing to the challenge of Li determination in the lattice. Here, a comprehensive analysis reveals different Li occupancies and related structural domains (Ni/Li exchange, Li<sub>a</sub>XO<sub>b</sub>, Li/Mn/X(Ni) ordering domains, X = Nb<sup>5+</sup>, W<sup>6+</sup>, and Mo<sup>6+</sup>) by using a combination of Li-sensitive characterization techniques. By introducing a Li-regulation strategy, the relative ratio of each domain is effectively tuned in the Ni-rich positive electrodes. Through tuning, two specific positive electrodes are designed, exhibiting notable improvement in battery cyclability. The specific Li structural units induce significant changes in redox mechanisms. This Li-occupancy-tuning approach highlights the necessity of focusing on Li distribution and opens up ideas for designing advanced Ni-rich positive electrodes with high durability.