Solid-state battery ≠ high nickel ternary + silicon-based lithium metal anode + solid-state electrolyte
Dr. Li Zheng, general manager of SAIC Qingtao, threw out the above views at the 2023 Gaogong Lithium Battery Annual Conference held in November, which is not consistent with the previous industry consensus.
Solid-state batteries have long been considered an ideal solution to the safety of lithium batteries and to improve energy density. The beginning of solid-state batteries is the "stacking buff" of the material system, selecting the positive and negative electrode materials with the highest gram capacity in the industry, and then replacing the separator and electrolyte with solid electrolyte.
Especially by 2023, there will be a serious overcapacity of battery homogenization, and power battery technology has reached a critical node for comprehensive upgrading. The highly-anticipated solid-state battery loading and production capacity planning continue to be disclosed, and the market is optimistic about the rising sentiment.
The risk of emotional overdraft industry expectations is worth being wary of.
Li Zheng said that there is still a misunderstanding of solid-state batteries in the industry, and it is not comprehensive to understand solid-state batteries from the material dimension alone, "The industrialization of solid-state batteries is a comprehensive upgrade from material system to battery structure to manufacturing process. ”
At present, the solid-state battery material system has not yet been formed, the production line equipment is not complete, and the solid-state battery industry chain is still in a state of chaos.
On the other hand, on the market side, at this stage, the positioning of solid-state batteries in the electrification market has changed from the layout of cutting-edge technologies to products that are about to be applied. After the change of context, the re-understanding of solid-state batteries has become the first step in adjusting the industrial strategy.
Recognise solid-state batteries
Li Zheng pointed out that solid-state batteries solve the limitations under the solid-liquid material system.
Looking back on the development of liquid batteries, the electrolyte system based on PC, EC and DMC solvents has been used from the beginning of commercialization to the present. In the process, the performance of the battery continues to improve, the cycle has developed from the initial 50 times to tens of thousands of times, the electrolyte part is constantly making a fuss in the additives, and in order to adapt to the electrolyte system, the positive and negative electrode materials are simultaneously treated to achieve the stability of the solid-liquid interface.
On the whole, the solid-liquid battery system is developing in the general direction of addition, but this development logic also brings limitations to the application of battery materials. And if you can jump out of the "stereotype" of high-nickel ternary cathode and silicon-based lithium metal anode, this comprehensive upgrade, solid-state batteries have a lot to offer.
Li Zheng said that the advantage of solid-state batteries is that the non-liquid system is no longer limited to 4The 2V cathode material can increase the cell voltage plateau, and the non-liquid system removes the premise of manganese dissolution, and high manganese materials can be used. In addition, the process is "subtracted" to simplify the process and promote energy saving and consumption reduction in the whole process.
Interface problems and lack of industrial chain
"Promising" is also facing the problem of core technology and industrial support.
The solid-solid interface problem is a pain point on the road to industrialization, there are both physical and chemical contacts in the interface, and how to take into account the conductivity, reduce side reactions, and reduce impedance is still the direction that the industry is still overcoming.
The industry is trying to commercialize various solutions, and in the process, a variety of technical routes have emerged for the key link of solid electrolytes. Li Zheng pointed out that in addition to the sulfide route, the chloride route is also worth paying attention to, with low cost and outstanding performance in process compatibility.
Filling the lack of the industrial chain and advancing technical research at the same time. Dr. Li Zheng pointed out that the solid-state battery industry chain currently lacks three major elements: development power, materials and technology.
OEMs lack motivation for the development of solid-state batteries. Due to common misunderstandings, for OEMs, solid-state batteries as electrification products still have no outstanding advantages in terms of cost and performance.
The new material industry in the new system of solid-state batteries is smallThe high manganese cathode and solid electrolyte** are not yet satisfied, and the development of lithium-containing anodes is slow.
The development of process technology lags behind the change of new material system of solid-state batteriesInnovative processes such as dry cathodes are not yet sufficient.
With the industrialization of solid-state batteries, the iterative update degree of the production line will be increased step by step, and the cost of the battery will also decrease step by step.
In the semi-solid stage, 30% of the production line equipment is renovated, and the cost is comparable to that of liquid lithium batteriesIn the solid-state (non-all-solid-state) stage, 60% of the production line equipment will be renovated, and the cost will be reduced by 20%;In the all-solid-state phase, 70% of the production line equipment will be renovated, and the cost will be reduced by 40%.
Solid-state batteries in the context of full electrification
The market's pursuit of next-generation power batteries comes from the goal of comprehensive electrification with deeper penetration and broader scope. It is not only to promote the market penetration of new energy vehicles, but also to realize the blueprint of electrification of transportation from land to sea and sky.
What are the new requirements for power batteries in the era of full electrification?Li Zheng believes that "the winner in the era of full electrification is not the "far ahead" of a single technology, but the "all-round champion" and "polygon warrior". ”
SAIC's internal evaluation system for batteries includes more than 20 indicators, which still fall into the four core aspects of cost, safety, performance, and durability, which are common in the market.
Li Zheng introduced that SAIC Qingtao's consideration of its own solid-state batteries will also promote the comprehensive development of solid-state batteries from eight dimensions: cell cost, thermal stability, energy density, consistency, charging performance, low temperature performance, cycle life, and calendar life. Battery products that evolve along the path of liquid-semi-solid-state will gradually meet the ideal indicators of the market.
Dr. Zhang Xiaofei, chairman of Gaogong Lithium Battery, said that at this stage, there is a development of battery products with cost as the highest guide in the marketThis kind of "cost-only theory" is worth being wary of. Ineffective investment in low-end production capacity should be avoided, and the development of next-generation battery technology, including solid-state batteries and dry-process electrodes, will help the industry move from volume to expansion.