Solid-state batteries are becoming an ideal power source for electric vehicles and consumer electronics due to their advantages in safety, energy density and charging speed. Although the market has bright prospects, its commercialization process is not smooth and still faces many challenges.
Commercialization of solid-state batteries will take time
On September 27, Lian Yubo, BYD's chief scientist, chief automotive engineer and director of the Automotive Engineering Research Institute, said at the 2024 World New Energy Vehicle Conference that the application of solid-state batteries may take another three to five years. Even if the advancement of solid-state batteries accelerates, lithium iron phosphate batteries will not be eliminated.
Lian Yubo pointed out that the technical parameters of lithium iron phosphate batteries have made significant progress, and their installed volume accounts for more than half. He predicts that in the future, solid-state batteries may be mainly used in some high-end new energy vehicles, while lithium iron phosphate batteries will still dominate a large number of popular new energy vehicles.
Zeng Yuqun, chairman and CEO of CATL, also mentioned at the 2024 World Power Battery Conference that if the numbers 1 to 9 are used to represent the technology and manufacturing maturity of solid-state batteries, 1 represents the beginning of entry into this field, and 9 represents mature technology. If large-scale production is possible, the current industry's highest level is only around 4.
The speeches of BYD and CATL provided a clearer perspective on the solid-state battery industry. Most of the so-called solid-state batteries currently on the market are actually semi-solid-state batteries. Actually technological breakthroughs in all-solid-state batteries are still mainly in the laboratory stage, and there is still a long way to go before practical applications.
The "solid-solid interface" problem
Solid-state batteries fundamentally differ from traditional liquid-state batteries in the type of electrolyte they use. Although liquid batteries have mature technology and are widely used, there is limited room for improvement in energy density. Solid-state batteries use lithium metal anodes and solid electrolytes, which not only improves the energy density of the battery, but also enhances safety. So it is regarded as a disruptive technology. technology of sexual potential.
China's research on solid-state batteries was earlier. It has begun exploring solid-state lithium batteries since 1976 and has long regarded it as a key scientific research topic. However, with the maturity and widespread application of liquid lithium battery technology, the research on solid-state batteries was once marginalized. In recent years, solid-state batteries have received renewed attention due to their advantages in energy density and safety.
Although solid-state batteries are highly anticipated, the road to commercialization has not been smooth sailing.
Zeng Yuqun, chairman of Ningde Times, mentioned that materials and chemical systems are particularly critical in research and development, especially the solid-solid interface problem, which is the main technical challenge currently facing the industry. This interface problem affects ion transmission efficiency and interface stability. The growth and volume change of lithium dendrites may lead to interface separation, thereby affecting the performance and safety of the battery.
The industry strives to overcome the problem of "solid-solid interface"
Faced with the problem of "solid-solid interface", many companies are actively exploring solutions. Tailan New Energy has developed the first automotive-grade solid-state lithium metal battery, using high-performance oxide composite solid-state electrolytes to effectively solve the interface impedance problem.
Yili New Energy and Narada Power have respectively overcome the problems of poor interface contact and internal resistance through innovative strategies.
Professor Zhang Xi's team at Yili New Energy has proposed a series of innovative strategies to address the challenges of the interface stability of all-solid-state battery anodes, covering multi-layer solid electrolyte design, SEI interlayer embedding and the application of high-capacity lithium alloy anodes. These strategies target four all-solid-state battery systems, sulfides, oxides, polymers, and halides, to improve the stability of the anode interface.
Narada Power recently showcased its all-solid-state battery products to the world at the RE+ American International Solar Energy Exhibition. Its solid-state battery technology solves the problem of "solid-solid interface" and can balance high specific energy and high safety. It can be used normally in an environment of -20℃-85℃, and the cost is only 10%-15% higher than that of ordinary lithium batteries.
It is understood that Narada Power's 20Ah all-solid-state battery has greatly improved the interface contact performance between the solid electrolyte and the electrode through the electrolyte sandwich structure design and in-situ film formation technology on the electrode surface, reducing the internal resistance of the cell and solving the "solid-solid interface" problem, effectively Improved cycle life, rate performance, etc. of all-solid-state batteries.
In order to further solve the industrialization problem of "solid-solid interface", the dense electrode dry process developed by Narada Power greatly reduces the electrode porosity, with a density as high as more than 80%, ensuring close contact between the electrode active material and the electrolyte, and the conductivity is significantly It is significantly higher than the wet electrode and also improves the battery energy density.
In addition, in terms of policy, the National Natural Science Foundation of China issued guidelines on February 26 that clearly support the research of all-solid-state batteries and are committed to solving the problem of solid/solid interface impedance. This move shows the government’s emphasis on the solid-state battery industry.
Summary
The commercialization of solid-state batteries not only relies on technological breakthroughs, but also requires close collaboration among all aspects of the industry chain, including material science, production technology, and cost control. In addition, factors such as policy support, market demand, capital investment and international cooperation will also jointly promote the development of solid-state battery commercialization.