An international research team has introduced an innovative cathode homogenization strategy for all solid-state lithium batteries, which can significantly improve life cycle and energy density
The latest news on solid lithium batteries
Solid-state lithium batteries are the new generation of electrochemical accumulation. On paper, this technology offers several advantages. For example, higher safety than lithium-ion batteries, high energy density, a wide operating temperature range and a long cycle life. Unfortunately, not everything that shines is gold. One of the main disadvantages of these rechargeables is the degradation mechanisms related to interface and mechanical problems. These include cathodic architecture.
The problem of heterogeneous composite cathode
In solid-state lithium batteries, traditional cathodes would suffer from very limited ion conduction. For this reason, electrochemically inactive additives are usually added that can increase this capacity. The main strategy is the introduction of solid electrolytes as an ionically conductive medium to build a heterogeneous composite cathode. However, the approach compromises energy density and cycle duration, resulting in complicated interface problems.
The solution comes today from a new research conducted by the Qingdao Institute of Bioenergy and Bioprocess Technology (QIBEBT) of the Chinese Academy of Sciences, together with experts from leading international institutions. Scientists have developed a cathode homogenization strategy using LTG 0.25 PSSe 0.2, a zero deformation material. This compound has excellent mixed ionic and electronic conductivity, ensuring efficient load transport during the discharge process without adding conductive additives.
The benefits of homogeneous cathode
LTG 0.25 PSSe 0.2 shows impressive performance parameters, including a specific capacity of 250 mAh/g and a minimal volume change of just 1.2%. A homogeneous cathode made entirely with this compound would allow solid-state lithium batteries to more than 20,000 stable operating cycles at room temperature and a high energy density of 390 Wh/kg at cell level.
Salt and forest waste for sodium-ion batteries
“Our cathode homogenization strategy challenges the conventional design of heterogeneous cathode,” explains Dr. Cui Longfei, co-first author of the study published in Nature Energy. “By eliminating the need for inactive additives, we improve energy density and extend battery life.”
This work represents progress not only for this segment. Other battery types, including solid-state sodium batteries, lithium-ion batteries, lithium-sulphur batteries, sodium-ion batteries, and fuel cells, also face challenges related to heterogeneous electrodes. These systems often suffer from mechanical and electrochemical incompatibilities, creating significant bottlenecks and degrading the overall battery performance.
The research can be consulted on Nature Energy.
