Researchers from Tohoku University and the High Energy Accelerator Research Institute (KEK) have developed a new composite lithium hydride fast-ion conductor as a solid electrolyte that can create an all-solid-state battery with the highest energy density to date.
One of the hottest topics in the battery field is nothing more than solid-state lithium batteries. A new innovation or breakthrough study appears almost every week. This is because all-solid-state batteries with lithium metal as the anode are safer than lithium-ion batteries. The charging time is shorter and the energy density is higher. It can also solve the current major problems of lithium-ion batteries, such as electrolyte leakage, flammability, and low energy density. Some car manufacturers have developed all-solid-state batteries instead of lithium-ion batteries. The investment report also listed all-solid-state batteries as an important promoter of changing the electric vehicle market.
However, compared with graphite anodes used in lithium-ion batteries, all-solid-state batteries using lithium metal as anodes can provide three times the capacity, but Northeastern University and the High Energy Accelerator Research Institute point out that solid-state electrolytes are all-solid-state batteries. The key is that the ionic conductivity and stability of the electrolyte determine the battery performance.
However, at present, because solid electrolytes tend to become unstable after encountering lithium metal, it will inevitably cause side effects at the interface, resulting in overall low conductivity after practical application of the battery, large internal resistance during ion transfer, and repeated charge and discharge Significantly reduce battery performance, which has become a major limitation for commercial mass production.
If the stability of the solid-state electrolyte and lithium ion conductivity can be solved, then the next-generation battery king status of all-solid-state batteries will be quite stable. Now, the research team has developed a hydride lithium superionic conductor as a solid electrolyte for all solid-state batteries, which makes the battery show high stability and high lithium ion conductivity.
In the past, composite hydrides have attracted a certain degree of attention from scientists, but usually they are based on the low ionic conductivity of composite hydrides, so they have never actually tried to combine composite hydrides with lithium metal anodes in batteries. The team finally confirmed that using composite hydride as a solid electrolyte can get along well with lithium metal anodes, and may finally have the opportunity to break the bottleneck of the development of all-solid-state batteries.