Lithium-sulfur (Li-S) batteries are widely recognized as one of the most promising next-generation energy storage technologies because of their exceptionally high theoretical energy density and specific capacity. However, their practical deployment has long been hindered by sluggish SRR kinetics and the "shuttle effect" caused by the dissolution and migration of LiPSs. These issues lead to severe capacity fading, poor rate capability, and limited cycle life.
To overcome these long-standing challenges, a research team led by Prof. Cunpu Li and Prof. Zidong Wei from Chongqing University, Prof. Bin Liu from City University of Hong Kong, and Prof. Minhua Shao from The Hong Kong University of Science and Technology, have developed an electron-injection-softened strategy to regulate the electronic structure of the sulfur host and achieve a nearly barrier-free cascaded SRR. Their work demonstrates a 2-Ah-level stable Li-S pouch cell, marking a major step toward the practical application of Li-S battery technology.
In conventional SRR, the reduction of S8 proceeds through a complex, multi-phase process—from soluble long-chain LiPSs to insoluble Li2S2/Li2S products—with high energy barriers. This sluggish conversion leads to polysulfide accumulation and the notorious "shuttle effect". To address this issue, the team led by Prof. Zidong Wei and Prof Cunpu Li constructed a Co9S8-Mn3O4@CNF in which electron injection from Co9S8 softens the Mn3O4 surface, enabling "soft to soft" orbital interactions between Mn and LiPSs. This softening effect facilitates delocalized electron transfer and promotes a cascaded conversion of LiPSs into Li2S2/Li2S, bypassing the conventional energy-barrier-limited liquid-solid transformation. As a result, the SRR proceeds through a nearly barrier-free pathway, allowing cascaded formation of Li2S2/Li2S and effectively suppressing LiPSs "shuttle effect".
"The electron-injection-softened strategy introduces a new perspective for designing sulfur hosts at the electronic structure level," said Prof. Cunpu Li. "By enabling direct orbital interaction between active sites and polysulfides, we can achieve nearly barrier-free conversion, which is crucial for realizing high-rate and long-life Li-S batteries."
Electrochemical tests reveal that the Co9S8-Mn3O4@CNF cathode delivers an initial specific capacity of 761 mAh g-1 at 5 C, maintaining stable cycling performance over 1000 cycles. More impressively, the team successfully assembled a pouch cell with a capacity of 2.22 Ah and an energy density of 389 Wh kg⁻¹ at a sulfur loading of 5.95 mg cm-2, demonstrating both high areal capacity and excellent stability.
The team concludes that this work not only provides a practical strategy to stabilize high-energy Li-S batteries but also offers fundamental insight into interfacial electron modulation for next-generation electrochemical energy storage devices.
Other contributors include Xiaoxia Tang, Hongrui Wang, Xun Jiao, and Dan He from Chongqing University.
This work was supported by the National Natural Science Foundation of China (Grant Nos. 92372202, 22478043, 22075033) and Guangzhou Science and Technology Bureau (2024A03J0609).
DOI Link:
https://doi.org/10.26599/NR.2025.94908170
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 8,000 articles. In 2025 InCites Journal Citation Reports, its 2025 IF is 9.4 (8.3, 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.
