The researchers at the Qingdao Institute of Bioenergy and Bioprocess Technology (QIBEBT) of the Chinese Academy of Sciences, in collaboration with international partners, have developed a groundbreaking cathode homogenization technique for all-solid-state lithium batteries (ASLBs).
This innovative approach brings about a substantial enhancement in the cycle life and energy density of ASLBs, signifying a significant leap forward in energy storage technology.
ASLBs currently encounter issues stemming from heterogeneous composite cathodes, necessitating the use of electrochemically inactive additives to improve conduction. Although these additives are essential, they diminish the energy density and cycle life of the batteries due to their incompatibility with the layered oxide cathodes, which undergo considerable volume changes during operation.
Researchers have formulated a revolutionary solution: a cathode homogenization technique using a zero-strain material, Li1.75Ti2(Ge0.25P0.75S3.8Se0.2)3 (LTG0.25PSSe0.2). This material demonstrates exceptional mixed ionic and electronic conductivity, ensuring efficient charge transport throughout the charging and discharging process without requiring additional conductive additives.
The LTG0.25PSSe0.2 material displays remarkable performance indicators, including a specific capacity of 250 mAh g–1 and a minimal volume change of merely 1.2%. An integrated cathode composed entirely of LTG0.25PSSe0.2 allows room-temperature ASLBs to achieve over 20,000 cycles of stable operation and a high energy density of 390 Wh kg−1 at the cell level.
“Our cathode homogenization strategy challenges the conventional heterogeneous cathode design,” said Dr. CUI Longfei, co-first author of the study from Solid Energy System Technology Center (SERGY) at QIBEBT. “By eliminating the need for inactive additives, we enhance energy density and extend the battery’s cycle life.”
“This approach is a game-changer for ASLBs,” remarked Dr. ZHANG Shu, co-first author of the study from SERGY. “The combination of high energy density and extended cycle life opens up new possibilities for the future of energy storage.”
Prof. JU jiangwei, co-corresponding author of the study from SERGY, added, “The material’s stability and performance metrics are impressive, making it a strong candidate for commercial applications in electric vehicles and large-scale energy storage systems.”
This breakthrough is backed by extensive testing and theoretical calculations. These analyses conclusively demonstrate the electrochemical and mechanical stability of the uniform cathodes, revealing no adverse chemical reactions or significant resistance increases after long periods of cycling.
In addition to ASLBs, various other battery types, such as solid-state sodium batteries, lithium-ion batteries, lithium-sulfur batteries, sodium-ion batteries, and fuel cells, encounter issues with diverse electrodes. These systems often experience mechanochemical and electrochemical incompatibilities, causing significant bottlenecks and compromising overall battery performance.
“The commercialization potential for high-energy-density ASLBs is now more achievable,” added Prof. CUI Guanglei, head of SERGY. “Our universal strategy for designing multifunctional homogeneous cathodes can overcome the energy, power, and lifespan barriers in energy storage, paving the way for real-world applications.”
Delving into the challenges of ASLBs, this strategy paves the way for future breakthroughs in energy storage technology. The team is poised to delve further into the scalability of the LTG0.25PSSe0.2 material and its incorporation into practical battery systems.
This work marks a pivotal step forward in battery technology, offering an optimistic glimpse into the future. The team’s pioneering approach is set to shape future research and development in energy storage, laying a robust groundwork for the next era of high-performance batteries.
Journal reference:
- Longfei Cui, Shu Zhang, Jiangwei Ju, Tao Liu, Yue Zheng, Jiahao Xu, Yantao Wang, Jiedong Li, Jingwen Zhao, Jun Ma, Jinzhi Wang, Gaojie Xu, Ting-Shan Chan, Yu-Cheng Huang, Shu-Chih Haw, Jin-Ming Chen, Zhiwei Hu & Guanglei Cui. A cathode homogenization strategy for enabling long-cycle-life all-solid-state lithium batteries. Nature Energy, 2024; DOI: 10.1038/s41560-024-01596-6