Driven by the Net Zero goals, the global new energy vehicle industry continues to develop rapidly. In 2024, global sales of new energy vehicles, including Battery Electric Vehicles (BEVs), Plug-in Hybrid Electric Vehicles (PHEVs), and Hydrogen Fuel Cell Vehicles, reached 16.29 million units, a year-on-year increase of 25%.

However, despite the booming development of the new energy vehicle industry, several key obstacles remain. One core issue closely related to the consumer experience is the insufficient driving range, which struggles to meet long-distance travel demands and has become a critical pain point the industry urgently needs to address.

To break through the range bottleneck, industry leaders and university laboratories are focusing on a new battery material—solid-state batteries—as a distinction from the current mainstream liquid lithium-ion batteries. Traditional liquid batteries use liquid electrolytes containing lithium as the core driving medium, which have limitations such as flammability, thermal runaway, lithium dendrite growth, and ion conductivity being significantly affected by temperature. These issues seriously impact battery performance and service life. Consumer feedback also indicates noticeably reduced battery performance in winter and summer, affecting the daily user experience. In contrast, solid-state batteries can not only effectively mitigate these risks but also offer higher energy density and faster charging speeds, significantly optimizing the user experience.

The key difference between solid-state and liquid batteries lies in the use of a solid electrolyte, which is also the current focus and challenge of research and development. Currently, solid-state batteries can be categorized into three main technical routes based on electrolyte type: oxide, sulfide, and polymer. Among these, sulfide solid electrolytes have become a mainstream R&D direction due to their high ionic conductivity, low interfacial resistance, good dendrite suppression capability, and relatively low production costs.

Lithium sulfide(Li₂S), as a key raw material for sulfide solid electrolytes, offers excellent ionic conductivity and stability, which can significantly enhance the battery's charge and discharge performance. Pure-phase Lithium sulfide(Li₂S) appears as white to yellow crystals with an anti-fluorite structure, a relative density of 1.66, a melting point of 938°C, and a boiling point of 1,372°C. It is soluble in water, ethanol, and acids, but insoluble in alkalis. As it hydrolyzes extremely easily in air, releasing hydrogen sulfide gas, Lithium sulfide(Li₂S) compounds do not exist directly in nature.

The commercial production of Lithium sulfide(Li₂S) still faces a series of technical bottlenecks. Its extreme instability in air imposes extremely high requirements for full-process inert atmosphere protection during production, storage, and transportation, significantly increasing process complexity and control costs. Furthermore, achieving the synthesis of Lithium sulfide(Li₂S) materials with high purity, low cost, large batch size, and consistent structure is a key obstacle lying between laboratory research and scaled-up supply.

Currently, the industrial production of Lithium sulfide(Li₂S) is still in the exploratory stage, with global capacity projected to be around 2,000 tons by 2025. The main production processes include solid-phase, liquid-phase, and gas-phase methods. Experiments have shown that batteries using Lithium sulfide(Li₂S) as the solid-state electrolyte can achieve approximately three times the range of traditional batteries, with a cycle life exceeding 10,000 charges, positioning it as a key development direction for next-generation battery materials.

After a decade of R&D, the core postdoctoral R&D team at Bais Chemical has successfully achieved the commercial production of Lithium sulfide(Li₂S) through independent research and development. Currently, this project has completed verification at the small-scale trial stage and is advancing with production line expansion to further optimize process parameters and technology for future large-scale industrialization.

From the revolutionary power source for new energy vehicles, to large-scale applications in energy storage power stations, and the persistent pursuit of longer battery life and smaller size in the consumer electronics field, solid-state battery technology centered on Lithium sulfide(Li₂S) is demonstrating immensely broad application potential. Cutting-edge exploration relies on the collaborative progress of the entire industry chain. Bais Chemical hereby extends a sincere invitation, looking forward to exchanging ideas and sparking innovation with friends in the new energy sector, as well as fellow travelers passionate about new materials for solid-state batteries, to jointly win the future of green energy.