The development of batteries has gone through a history of nearly two hundred years, and now lithium-ion batteries are the most outstanding secondary energy storage batteries. High operating voltage, fast charge and discharge characteristics, long cycle life, no memory effect and many other advantages make it the first choice for large-scale applications of digital products and electric vehicles today.
Although the performance of lithium-ion batteries is excellent, there are also challenges and obstacles that are difficult to cross in development: the structural characteristics of the battery limit the performance of the battery. The existing battery structure is the root cause of battery aging and safety hazards.
The principle of battery power generation is that the two electrode materials exchange ions with each other in the electrolyte, but because this structure will also make its reaction interface always exist, the battery is in a state of continuous operation, resulting in a situation of easy aging and safety hazards.
For example, electric vehicles nest in winter because the battery fails in the low temperature situation. Materials scientists and battery engineers have proposed many approaches to battery materials. For example, a large number of organic solvents are incorporated into the electrolyte to reduce the solidification temperature of the electrolyte. However, this makes the electrolyte more flammable, sacrificing the safety of the battery.
Some scientists have also tried to replace the electrode material, but the energy of the battery has increased, but it cannot resist thermal runaway; if it is fast charged, it will cause the fire of the battery interface to be too high, and its safety cannot be guaranteed. Solved from the system idea of optimizing battery management, it has brought about a decrease in energy density and an increase in unit cost.
Want to make the battery low temperature high activity and high temperature stability of the demand contradiction, it seems that the battery also has a fish and bear paw can not be both the obstacle, energy density, safety, fast charging and other elements can not be perfectly integrated in the battery body. If these problems are solved, the scale development of new energy vehicles will revolutionize the industry that has reshaped the automobile for a hundred years.
Therefore, the ultimate development goal of power batteries is also moving towards safety, high energy density, good cycle performance, fast charging speed and other advantages.
Solid-state batteries, as the new lithium battery terminator direction, are becoming the killer of new energy vehicles to kill fuel vehicles.
The value of power batteries is advanced
When can new energy vehicles replace fuel vehicles, the market in the field of power batteries is recognized as an answer: the energy density of the battery system of existing electric vehicles has doubled, from the general 160wh/kg to 400wh/kg. To solve the problem of energy density of the battery, the solution must be the innovation of the power battery.
We know that the mainstream power batteries in the electric vehicle market are ternary lithium batteries and lithium iron sulfate batteries, if classified according to the physical state of the electrolyte, these two batteries are typical liquid batteries. If you want to eliminate mileage anxiety and innovate the new energy vehicle market, solid-state battery performance characterization is the goal of power battery development. Solid-state batteries, also known as the new direction of the development of lithium batteries in the future.
The popular choices in the field of power batteries are ternary lithium and lithium iron sulfate are not perfect choices. Ternary lithium batteries, high energy density, but poor high temperature resistance, lithium iron phosphate batteries, high safety, but low energy density upper limit. Liquid lithium-ion batteries generally have safety hazards such as electrolyte oxidation, electrode expansion, and high temperature runaway, and can only sacrifice energy density in exchange for stability. Solid-state batteries can be compatible with the shortcomings of both: both to meet the needs of energy density and to take into account safety.
Solid-state batteries, because of the use of solid matter as the electrolyte, there is no continuous reaction interface, by-products will not dissolve in the interface, so it will have better stability and cycle characteristics. At the same time, the problem of drying up and leakage faced by liquid electrolytes will not exist. This makes solid-state batteries far superior to ternary lithium batteries and lithium iron phosphate in terms of safety and life cycle.
In addition, solid-state batteries also have the characteristics of high temperature resistance, non-corrosion, small size and large energy density, which avoids the main weaknesses of traditional liquid lithium batteries. According to reports, the cruising range of a solid-state car can reach 1000 kilometers, charging only takes 10 minutes, and over time, the degradation of solid-state batteries will be less.
All-solid-state batteries use solid electrolytes to be relatively safer and better performing, while traditional liquid lithium-ion batteries are gradually unable to meet the standards of advanced technology: both to increase the cruising range and more secure. Therefore, all-solid-state batteries have become a new upsurge in the development of the power battery industry.
Rushing to the scene: the opportunity to occupy the market
In November 2020, the "New Energy Vehicle Industry Development Plan (2021-2035)" issued by the General Office of the State Council clearly requires that the research and development and industrialization of solid-state power battery technology be accelerated. It is predicted that by 2030, the global solid-state battery market will exceed 6 billion US dollars (about 38.3 billion yuan), and the proportion of the Chinese market will exceed 50%.
The good performance indicators of solid-state batteries in the laboratory mean rich commercial value, which also becomes the driving force for enterprises to accelerate their layout and seize the commanding heights of technology. Domestic and foreign enterprises and institutions have put on the agenda for the research and development and mass production of power batteries.
Toyota's layout in the power battery is also earlier, Toyota's vehicle-grade solid-state battery has more than 1,000 patents, ranking the forefront in the world, and most of them are invention patents with high gold content. At CES2022, Gill Pratt, Chief Scientist of Toyota and Director of the Toyota Research Institute, reiterated that the first Toyota car with solid-state battery technology will arrive around 2025.
Thomas Schmall, chief technology officer of Volkswagen Group Parts, said in an interview last year that Volkswagen has high hopes for the development of a new generation of solid-state batteries, and the company hopes to form a complete solid-state battery sales model in 2025, supplying solid-state batteries to the market, and plans to establish 6 large-scale battery factories in Europe by 2030, with a total annual production capacity of 240GWh.
The BMW Group announced plans to achieve mass production by 2030; LG Energy is also developing all-solid-state batteries and is expected to achieve mass production in 2026.
The development of domestic solid-state batteries is also in full swing, and the technical route is all solid and semi-solid. The battery industry leader Ningde Era has previously disclosed two patents related to solid-state batteries, and declared in May last year that it is possible to make samples of solid-state batteries, but there is still a long way to go before commercialization, and it is expected that it will be launched to the market in 2030. SAIC Motor announced in June last year that it would launch high-safety, high-energy-density, commercially-oriented solid-state lithium batteries in 2025.
The players who choose to target semi-solid-state research and development are Weilan New Energy, Qingtao Development, Guoxuan Hi-Tech, Ganfeng Lithium Battery, etc. Although they also have all-solid-state battery production lines, the all-solid-state batteries that have been mass-produced are mainly used in consumer electronics, special power supply and other fields. Semi-solid-state batteries that have been discontinued for use in new energy vehicles are currently in the verification and testing stage.
Weilai previously advertised the use of solid-state batteries, making the industry boil. After the listing, this so-called solid-state battery also presents the final true face, not the industry is looking forward to the waiting for the all-solid-state battery, Weilai Li Bin played a commercial packaging term, equipped with ET7 sedan battery pack is actually a semi-solid-state battery. But the attention and discussion caused by the gimmick also made Weilai's new car out of the limelight, and the battery with a range of more than 1000km made people see the potential of solid-state batteries.
Whether it is the timetable set by car companies, or the mass production time given by industry researchers and experts, it points to 2025 and 2030, but there is no sign of advance at present, with the results of the actual car company test now, there is a trend of continuing to postpone to 2030. We see that from walking out of the laboratory to the scale landing, it still needs a period of dormant development time, and the actual landing of large-scale mass production is obstructed and long.
Large-scale mass-produced turtle crawling at speed
Compared with other lithium-ion power batteries, the technical indicators of solid-state batteries are superior, but these data are also the greenhouse indicators in the laboratory. In the process of actual mass production, there are still many bottlenecks that have not yet been overcome.
1. The technical indicators of solid-state batteries still need to be improved. The ionic conductivity of solid electrolytes is low, charging is relatively slow, the contactability and stability of the solid/solid interface are poor, and the electrolyte is sensitive to air.
2. The manufacturing process is complex and the production process is immature. For example, the manufacture of solid-state batteries of oxides and sulfide electrolytes, belongs to the porous ceramic materials, such materials are characterized by brittleness, want to process into a very thin electrolyte is very difficult, a little careless will break.
3. The manufacturing cost is high. The preparation process of all-solid-state batteries is complex, and the solid electrolyte is more expensive, and the cost of all-solid-state electrolyte lithium power batteries is higher at this stage.
4. The industrial chain is not yet complete, and it is difficult to produce on a large scale. At this stage, the solid-state battery is mostly a greenhouse product in the laboratory, and there are only a few batteries that have actually been tested, and with the existing process level and equipment capabilities, the yield of the finished product cannot be guaranteed, not to mention the large-scale mass production market.
Solving these realistic bottlenecks is not so easy. Fisker, which has been deeply involved in the research and development of solid-state batteries for several years, said at the beginning of last year that it would abandon the development of all-solid-state batteries, and this decision also means that years of research on solid-state batteries have been adrift. Lithium battery unicorn Mittel Solid Energy (SES) also abandoned the research and development of all-solid-state battery technology and chose the semi-solid-state battery route of solid-liquid hybrid. In the final stage, the old players in these solid-state batteries choose to give up, which also shows to a certain extent that the final research and development sprint stage of solid-state batteries is more difficult and dangerous than the 90% of the mileage that has been completed.
In short, for solid-state batteries, whether it is the energy density, cycle life, safety, cost and other elements on the technical indicators, which one is missing is a roadblock to the road of scale commercialization.
Whether the company still adheres to the all-solid-state battery route or chooses the semi-solid-state route, there is uncertainty about the technical route of the solid-state battery. The mainstream view in the industry is that semi-solid-state batteries may be able to achieve mass production around 2025, but it will take at least 10 years for all-solid-state batteries to be fully commercialized. Ten years of timeline development, solid-state batteries are ultimately the ultimate route of power batteries, and no one can be 100% sure.
Industrial products from research and development to verification and landing, there is no ten years to lay the foundation is not out. Solid-state batteries are still in the process of exploration from materials to structures to manufacturing technologies. As an emerging power battery choice, it also takes time to precipitate and brew. In this way, we can build a long-term range for the mileage of new energy vehicles, subvert the century-old industry of innovative automobiles, and also contribute to the ecological construction of green travel.