Cobalt-free LiNiO 2 (LNO) is considered a promising cathode for its high energy density and cost-effectiveness. However, its structural instability under deep delithiation severely limits practical application in next-generation lithium-ion batteries (LIBs). Microstructure engineering enhances structural stability through precisely controlled lattice modulation strategies, particularly via high-valence element doping which effectively stabilizes the crystal framework through strong bonding characteristics and charge compensation effects.
A collaborative research initiative between Southwest Petroleum University's Surface Engineering and Connection Technology Group and Team of Gaolong Zhu and Tiening Tan from Prof. Ouyang Minggao Academician Workstation has proposed a high-valence Mo 6+ doping strategy to simultaneously improve mechanical robustness and electrochemical stability. LNO devoid of the Mn/Co-mediated stabilization, exhibit severe capacity decay and structural deterioration under aggressive delithiation, such as high temperatures or voltages, which may induce an escalation of internal stresses and subsequent collapse of the layered structure. While the literature extensively covers strategies to stabilize layered oxides under high voltages, current methods still exhibit pronounced limitations in high-temperature operation.
The team published their review in Nano Research on December 30, 2025.
“In this research paper, we outline some of our team's efforts to address mechanical failure in LNO cathodes under high-temperature deep delithiation conditions. Through systematic investigation of electrochemical performance, fundamental physicochemical properties, and cycling durability, we demonstrate how stress relief caused by enhanced grain boundary interactions contribute to remarkable performance enhancement. Furthermore, by integrating electrochemical-mechanical coupling simulations with first-principles calculations, we elucidate the atomic-scale mechanisms governing Mo dopant incorporation and its stabilization effects under elevated temperature operation,” said Xiaowen Chen, corresponding author of this paper, professor in the School of New Energy and Materials at Southwest Petroleum University.
LIBs are widely regarded as the foremost energy storage technology in electric vehicles and stationary storage systems, owing to their exceptional energy density, robust voltage characteristics, and long-term cycling durability. LNO has emerged as a critical material in advanced energy storage systems, given its high reversible capacity, resource sustainability, cost competitiveness, and environmental friendliness.
To address mechanical degradation in cathode materials under deep delithiation conditions, the research team enhances structural stability via precisely controlled grain boundaries strategies. “Assessing the structural stability of layered cathodes at elevated temperatures requires rigorous evaluation of key failure mechanisms, such as crystallographic phase transitions, mechanical degradation, and electrode-electrolyte interfacial side reactions. To date, investigations into the structural stability of LNO cathodes at elevated operating temperatures (> 45 ℃) have been limited. The regulation mechanism of our study on the mechanical-electrochemical coupling behavior under deep delithiation compensates for the lack of attention to high-temperature deep delithiation scenarios in existing research,” said Gaolong Zhu, corresponding author in the Prof. Ouyang Minggao Academician Workstation & Sichuan New Energy Vehicle Innovation Center.
Solid-state batteries (SSBs), among the most promising energy storage technologies, have attracted significant research interest. Moreover, most theoretical studies remain concentrated on their high-temperature performance. Notably, LNO are regarded as a leading candidate for all-solid-state batteries (ASSBs), a status attributed to their exceptional electrochemical properties. Team of Gaolong Zhu and Tiening Tan demonstrated advances and challenges on SSBs in previous studies. Gaolong Zhu said, “Suppressing mechanical degradation in layered cathodes at elevated temperatures is a pivotal challenge demanding focused research in materials development.”
The research team establishes high-valence Mo 6+ doping as an effective strategy for stabilizing LNO under deep delithiation conditions through a grain boundary strengthening mechanism. “High-valence element doping (e.g., Nb, Ta, W, Mo) exhibits superior efficacy—a phenomenon well-documented in previous research. However, these advantages are increasingly offset by emerging challenges as nickel content rises. Current doping strategies are inadequate in addressing the propagation of mechanical fractures during deep delithiation and the inherent trade-off between structural stabilization and the Li + mobility degradation. Mo 6+ doping is strategically selected for LNO cathodes based on valence adaptability and atomic dimensions,” said Tiening Tan, corresponding author in the Prof. Ouyang Minggao Academician Workstation & Sichuan New Energy Vehicle Innovation Center.
Other contributors include Tianrui Cui, Ding Li, Thomas Hirtz, Jiandong Xu, Yancong Qiao, Haokai Xu, He Tian and Yi Yang from the School of Integrated Circuit and the Beijing National Research Center for Information Science and Technology (BNRist) at Tsinghua University in Beijing, China; and Houfang Liu from the BNRist at Tsinghua University.
This work was supported by by the National Key R&D Program of China (2021YFC3002200 and 2022YFB3204100), the National Natural Science Foundation of China (U20A20168, 51861145202, 61874065, and 62022047).
About Nano Research
Nano Research is a peer-reviewed, open access, international and interdisciplinary research journal, sponsored by Tsinghua University and the Chinese Chemical Society, published by Tsinghua University Press on the platform SciOpen. It publishes original high-quality research and significant review articles on all aspects of nanoscience and nanotechnology, ranging from basic aspects of the science of nanoscale materials to practical applications of such materials. After 18 years of development, it has become one of the most influential academic journals in the nano field. Nano Research has published more than 1,000 papers every year from 2022, with its cumulative count surpassing 7,000 articles. In 2024 InCites Journal Citation Reports, its 2024 IF is 9.0 (8.7, 5 years), and it continues to be the Q1 area among the four subject classifications. Nano Research Award, established by Nano Research together with TUP and Springer Nature in 2013, and Nano Research Young Innovators (NR45) Awards, established by Nano Research in 2018, have become international academic awards with global influence.
Nano Research
Enhancement of grain boundary interactions to promote mechanical stability of LNO under deep delithiation conditions
30-Dec-2025