Researchers at the Qingdao Institute of Bioenergy and Bioprocess Technology (QIBEBT) of the Chinese Academy of Sciences, along with international collaborators, have made a significant breakthrough in enhancing all-solid-state lithium batteries (ASLBs).
Their innovative method, called the cathode homogenization strategy, was detailed in a recent publication in Nature Energy.
This new approach greatly improves the lifespan and energy density of ASLBs, marking an important advancement in energy storage technology.
Current ASLBs face problems due to the need for electrochemically inactive additives in their composite cathodes.
These additives are necessary to enhance conduction but reduce the batteries’ energy density and cycle life.
The incompatibility with layered oxide cathodes, which undergo significant volume changes during operation, further complicates the issue.
To solve this, researchers developed a cathode homogenization strategy using a material called Li1.75Ti2(Ge0.25P0.75S3.8Se0.2)3 (LTG0.25PSSe0.2).
This zero-strain material has excellent mixed ionic and electronic conductivity, ensuring efficient charge transport throughout the charging and discharging process without needing additional conductive additives.
The LTG0.25PSSe0.2 material shows impressive performance, including a specific capacity of 250 mAh g–1 and minimal volume change of just 1.2%. A homogeneous cathode made entirely of LTG0.25PSSe0.2 allows ASLBs to achieve over 20,000 cycles of stable operation and a high energy density of 390 Wh kg−1 at room temperature.
Dr. Cui Longfei, co-first author of the study from the Solid Energy System Technology Center (SERGY) at QIBEBT, stated, “Our cathode homogenization strategy challenges the conventional heterogeneous cathode design. By eliminating the need for inactive additives, we enhance energy density and extend the battery’s cycle life.”
Dr. Zhang Shu, another co-first author of the study from SERGY, added, “This approach is a game-changer for ASLBs. 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, emphasized, “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.”
The researchers conducted extensive testing and theoretical calculations to confirm the electrochemical and mechanical stability of the homogeneous cathodes. They found no adverse chemical reactions or significant resistance increases after prolonged cycling.
Beyond ASLBs, other battery types, including solid-state sodium batteries, lithium-ion batteries, lithium-sulfur batteries, sodium-ion batteries, and fuel cells, face similar challenges with heterogeneous electrodes. This new strategy could help overcome these issues.
Prof. Cui Guanglei, head of SERGY, stated, “The commercialization potential for high-energy-density ASLBs is now more achievable. 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.”
This groundbreaking work sets the stage for future innovations in energy storage technology and is expected to influence future research and development, providing a strong foundation for the next generation of high-performance batteries.
