Key problems of all-solid-state lithium batteries have been broken through

Recently, China Institute of Atomic Energy Science of China Nuclear Group joined hands with Shenzhen International Graduate School of Tsinghua University, relying on China Advanced Research Reactor, using neutron depth profile analysis technology, to accurately reveal the key defects of traditional single-layer cathode of all-solid-state lithium batteries. For the first time, the related research directly observed and quantitatively confirmed the significant vertical lithium concentration gradient through experiments, and realized the uniform distribution of lithium concentration in the thickness direction of the electrode, which provided a strong experimental basis for the core design of the gradient electrode, and was of great significance for promoting the basic scientific knowledge and engineering application of all-solid-state lithium batteries. Relevant research results were published in the international academic journal Energy and Environmental Science. All-solid-state lithium batteries, known as the "next generation energy revolution" technology, fundamentally eliminate the risks of leakage and fire that may occur in traditional lithium batteries, and significantly improve their safety, but their commercial applications still face many "roadblocks", such as cycle stability and energy density improvement. To solve the above problems, it is necessary to understand the internal reaction mechanism of the electrode. In the past, the "visual" detection of lithium has always been a pain point in the industry, and has become a key link restricting the performance improvement of all-solid-state lithium batteries. Experts from the China Institute of Atomic Energy, CNNC, said that as an advanced nuclear analysis technology, neutron depth profiling technology is a branch of neutron activation analysis technology, which can use neutron beams to "see through" the interior of materials, just like doing a non-destructive "CT scan". Neutrons are extremely sensitive to light elements such as lithium, and the whole "scanning" process has the characteristics of high sensitivity, high resolution and non-destructive. In the study of battery materials sensitive to air/moisture, neutron depth profiling technology has incomparable advantages-it can track the transmission process of lithium ions during battery charging and discharging, just like installing a "perspective of lithium distribution". It provides precise "navigation" for optimizing battery design and improving battery performance.