Toyota Motor Corporation recently announced during a technical briefing that they have identified promising materials that could enable the commercialization of solid-state batteries between 2027 and 2028, with plans to introduce pure electric vehicles equipped with solid-state batteries to the market. However, due to Toyota not disclosing convincing technical details, it has raised skepticism in the public.
Solid-state batteries offer not only high safety and energy density but also excellent performance in extreme temperature conditions. These advantages have generated considerable anticipation, as solid-state batteries are regarded as the next-generation power source and a strategic high ground for countries worldwide. Three decades ago, the Oak Ridge National Laboratory in the United States claimed to have developed solid-state batteries, but unfortunately, large-scale production has not been achieved to date. In recent years, as the global electric vehicle market has surged, many companies have announced progress in solid-state battery production, only for the news to fade away after being publicized.
Solid-state batteries can currently be classified into three technological pathways based on the material systems. Japan and South Korea are focused on the sulfide system, Europe primarily pursues the polymer route, and China is predominantly centered on the oxide system. Among these, Japanese and South Korean companies represented by Toyota, Samsung SDI, and Hitachi have accumulated significant technological expertise and possess an evident early-mover advantage. Moreover, there is a clear trend of collaborative research and development. However, all three technological pathways have corresponding fundamental shortcomings that need urgent resolution.
Specifically, sulfide electrolytes exhibit poor air stability and can generate toxic gases when exposed to air. Additionally, the synthesis, storage, transport, and post-processing of sulfide electrolytes heavily rely on inert gas or dry chambers due to potential structural degradation and electrochemical performance degradation. Polymer electrolytes exhibit low ionic conductivity at room temperature, necessitating high-temperature charging for polymer solid-state batteries, significantly limiting their commercial viability. Most oxide electrolytes possess a wide electrochemical stability "window" and better oxidative stability. However, to ensure good contact between rigid oxide electrolytes and cathode materials, high-temperature sintering is often required, or else it may lead to severe interfacial chemical reactions. Furthermore, some oxide electrolytes face issues related to lithium dendrite growth.
Cost is also a significant hurdle for companies to overcome. Currently, the cost of semi-solid-state batteries is significantly higher than that of commercial liquid-state batteries. According to industry research and calculations, taking NCM811 liquid cells and NCM811 semi-solid cells as examples, the cost of semi-solid cells is approximately 80% higher than that of liquid cells. Among the factors contributing to this cost increase, the solid-state electrolyte's cost is the primary factor and constitutes about 50% of the total cost. Due to factors such as changes in electrolyte materials, alterations in production processes, and insufficient experience in quality control, the engineering validation cycle becomes extended, making the cost of full solid-state batteries even higher than that of semi-solid-state batteries.
Five main indicators determine whether a power battery can ultimately be mass-produced: energy density, charge/discharge rate performance, cost, safety, and cycle life. Breakthroughs in laboratory research typically achieve significant progress in one or several of these indicators. However, only when all five indicators meet the requirements can the battery be considered for mass production. In other words, for the current progress in the research and development of major companies, solid-state batteries may seem to be on the verge of taking off, but the road ahead is still long, and the challenges associated with achieving mass production are significant.
Compared to structural innovation, material improvement is slower and undoubtedly more challenging. Nevertheless, difficulty should not deter us from making progress. We often say that we should do "difficult but right things," and there is wisdom in this statement. From the perspective of technological innovation, during the development of the new energy vehicle industry, battery technology has played a leading role. The reason why China's new energy vehicle industry can lead globally is because we have surpassed others in power battery technology, giving rise to global power battery giants like CATL.
In the industrial transformation driven by the "dual-carbon" goals, innovation in power batteries has become the key to strengthening the competitiveness of the new energy vehicle industry, enhancing the competitiveness of national industries, and consolidating corporate competitive advantages. Whether it is an early leader in the new energy vehicle industry, a latecomer, or an entity within the power battery supply chain, they are all focusing on new technologies and making arrangements for solid-state batteries. This presents both a formidable challenge and a rare opportunity. The vast market advantage, leading overall industry competitiveness, and continually rising innovation capabilities provide China with the conditions to secure the strategic high ground in power batteries.
Request a Quote
