关键词: 固态电解质, 全固态锂电池, 专利分析

Abstract:

Solid-state lithium batteries have become the primary focus in the field of lithium batteries due to their high safety, high energy density, long cycle life, and wide operating temperature range. Using solid electrolyte as the core component of a solid battery is the primary difference from a traditional liquid battery. The solid electrolyte largely determines the performance parameters of the solid lithium battery, including the power density, cycle stability, safety performance, high and low temperature performance, and service life. Therefore, further study of solid electrolytes is ongoing in research institutions of various countries, large electronics companies, and automobile manufacturing companies. This article systematically introduces three types of solid electrolytes that are favored by the industry: Polymer, oxide, and sulfide, and analyzes the latest progress and reported results for each. Among these three types, polymer electrolytes demonstrate good viscoelasticity, excellent machining performance, are lightweight, and transmit lithium ions through the process of "complexation and decomplexation". Oxide solid electrolytes can be found in the crystal state or the glass state. NASICON, perovskite, garnet, and LISICON electrolytes are examples of crystal state electrolytes, while the LiPON electrolyte used in thin film batteries is a popular type of glass oxide electrolyte. Compared with oxide electrolytes, sulfide solid electrolytes exhibit higher ionic conductivity because sulfur ions have a large radius and strong polarization, and for this reason have attracted much attention in recent years. To analyze the development of these electrolytes, a search for solid-state electrolyte patent applications for all-solid-state lithium batteries was performed in the Derwent Innovations Index patent database (DII). After 2015, patent applications for solid electrolytes exhibited a stage of rapid growth. The number of patent applications from Japanese and Korean companies was exceptionally high, from companies such as Toyota, Fuji, and Samsung. These companies have mastered the advanced technology of solid-state lithium batteries. Tracking patent applications allows readers to understand the level and progress of solid electrolytes in different regions, and helps enterprises and universities to seek relevant cooperation and increase investment in related research fields. At present, mass production of solid electrolytes still faces many technical difficulties. It is our hope that in the future, research on solid electrolytes can overcome the technical bottlenecks, realize the industrialization of all-solid lithium batteries, and contribute to the clean and safe use of energy around the world.

Key words: solid electrolyte, all-solid lithium battery, patent analysis