国金证券：硫化物为全固态电池主力路线 产业化进程提速

Core Viewpoint - Solid-state batteries are the trend due to high safety and high energy density, with a focus on sulfide routes aiming for energy density of 400Wh/kg and cycle life exceeding 1000 times, targeting small batch production for cars by 2027 and large-scale production by 2030 [1][2] Group 1: Solid-State Battery Development - The current focus of all-solid-state batteries is on sulfide routes, which offer the highest room temperature conductivity and excellent mechanical properties, making them the theoretically ideal solid electrolyte material [2] - The main performance goals for solid-state batteries include achieving an energy density of 400Wh/kg and a cycle life of over 1000 times, with a roadmap to small batch production by 2027 and large-scale production by 2030 [2] Group 2: Sulfide Electrolyte Characteristics - Sulfide electrolytes have various forms, with lithium sulfide silver germanium ore structure being the mainstream due to its low cost, high room temperature conductivity, simple synthesis, and high reproducibility [3] - The electrochemical stability of sulfide electrolytes is a challenge, with narrow electrochemical windows and poor interfacial properties, requiring improvements through doping and coating [3] - Solid-state synthesis methods are advantageous for high ionic conductivity, while liquid-phase methods are easier for large-scale production but yield lower conductivity [3] Group 3: Lithium Sulfide as Core Material - The purity of lithium sulfide is critical for the preparation of sulfide electrolytes, with over five mainstream preparation processes evaluated for purity, safety, and economic viability [4] - The lithium sulfide synthesis process stands out for its product indicators, with carbon thermal reduction, hydrazine reduction, and liquid-phase methods showing significant advantages and entering engineering validation stages [4] Group 4: Market Landscape and Competition - The landscape for lithium sulfide and sulfide electrolytes is competitive, with leading lithium battery companies establishing industry matrices, including Ganfeng Lithium, Tianqi Lithium, and others [5] - Startups are emerging rapidly, and semiconductor companies are extending their technology to the lithium sulfide supply chain [5] - The competition in the sulfide electrolyte market is expected to be intense, with battery manufacturers actively researching sulfide electrolytes and many material companies involved [5]