[There is a saying in the industry that the cost of all-solid-state batteries is more than 4 times higher than that of current lithium batteries. ]
Solid-state battery technology has ushered in a breakthrough.
Recently, a Harvard University research team has developed a new solid-state battery that can be recharged 10,000 times, is expected to be fully charged within 3 minutes, and can last for 20 years.
The solid-state battery uses lithium in pure metal form, using solid electrodes and a solid electrolyte, rather than the liquid or polymer gel electrolytes found in lithium-ion batteries. In the lab, the battery prototype was able to successfully complete 5,000 to 10,000 charge cycles. The Harvard research team's research on solid-state lithium metal batteries can be traced back to May last year, but the technology at that time remained at the level of "full charging within 10 to 20 minutes and battery life of 10 to 15 years".
The design of this battery is inspired by the classic British sandwich. If you imagine the battery as a sandwich, first a layer of bread (lithium metal anode), then lettuce (graphite coating), then a layer of tomatoes (first electrolyte) and a layer of bacon (second electrolyte), Finally another layer of tomatoes and a layer of bread (cathode).
The research team believes that typically lithium metal anodes in other solid-state designs develop dendritic growths that can gradually penetrate through the electrolyte to the cathode, causing a short circuit in the lithium-ion battery. That is to say, the dendrites or dendrites produced during the use of lithium-ion batteries are the root cause of battery fires. While the sandwich's multilayer structure prevents dendrites from forming, in this design, dendrites grow in the "lettuce" and "tomato" but stop at the "bacon". The "bacon" barrier prevents dendrites from passing through and shorting out the cell, preventing failure.
“We set out to commercialize this technology, which is unique compared to other solid-state batteries. In the lab, we have achieved 5,000 to 10,000 charge cycles over the life of the battery, and now even comparable The best batteries in the product also have only 2,000 to 3,000 charge cycles, and we don’t think there are any fundamental limits to scaling up battery technology, which could be a game-changer.” John A., Harvard University. Xin Li, associate professor of materials science at the Paulson School of Engineering and Applied Sciences, said.
Now, Adden Energy, a startup founded by the research team, has announced that it has received an exclusive technology license from Harvard University's Office of Technology Development to advance the commercialization of the technology, with the goal of shrinking batteries into palm-sized " pouch battery”, whose components are encapsulated in an aluminum-coated film. However, Xin Li said in an interview with the media last year that the commercialization of the technology is still years away and faces many challenges.
Solid-state battery refers to a lithium-ion battery using a solid-state electrolyte, which has higher safety and energy density, and is considered to be the technical direction of the next-generation electric vehicle power battery. At this stage, solid-state batteries are ahead of ternary lithium batteries in technical indicators. Judging from the current industrial layout, many international car companies such as Toyota, BMW, Volkswagen, and Hyundai are all deploying in the field of solid-state batteries and increasing their investment in the field of solid-state batteries. In addition, car companies and battery manufacturers have joined hands to overcome difficulties. Toyota is cooperating with Panasonic, Volkswagen has invested in the US battery start-up QuantumScape (Quantum Landscape), and Ford and BMW have invested in Solid Power (solid-state power company). Solid Power's all-solid-state battery can theoretically achieve a range of up to 2 times that of lithium batteries. BMW plans to start road testing of vehicles equipped with all-solid-state batteries before 2025 and launch them before 2030. Following the cooperation with Hydro Quebec (Hydro Quebec), Mercedes-Benz is now also working with Factorial Energy (Factorial Energy) to develop solid-state batteries.
However, mass-produced solid-state batteries have not yet been seen in cars. As early as 2011, Toyota stated that it will launch solid-state batteries from 2015 to 2020. It believes that solid-state batteries will completely make up for the cruising range of new energy vehicles, while also vigorously promoting the speed of new energy vehicles. However, to this day, solid-state batteries have not been formally applied. Toyota expects to achieve mass production and application in 2025, and LG New Energy expects to achieve mass production of all-solid-state batteries in 2026.
"For all-solid-state batteries, there are still some technical difficulties." Dong Sixiao, CEO of High Energy Times, said in an interview with a reporter from China Business News. First, the problems of batch, low-cost, and stable synthesis of electrolytes have not been effectively solved. Second, The problem of large internal resistance caused by the solid-solid interface problem has not been solved, and the third is that the corresponding equipment and process have not yet been finalized.
Among them, the problem of solid-solid interface is divided into physical level and chemical level. At the physical level, the volume of powder particles will become larger or smaller during the battery charge-discharge cycle. It is easy to create a gap between the layer and the layer, resulting in poor contact, affecting the transmission of ions and electrons, and the internal resistance of the battery will increase, and polarization problems will occur during the charging and discharging process, resulting in a decrease in rate performance. At the chemical level, if the sulfide electrolyte material is not properly selected, the sulfide electrolyte is prone to chemical reactions with positive and negative electrode materials, conductive agents, and binder materials. Therefore, in the electrochemical environment, lithium ions will be generated at the interface. The reaction product with relatively low conductivity leads to an increase in the internal resistance of the battery and a decrease in the rate performance of the battery.
The mass production time of all-solid-state batteries may be in 2030.
Ouyang Minggao, academician of the Chinese Academy of Sciences and vice-chairman of the China Electric Vehicle Association of 100, said before that materials such as materials must be accumulated and developed.
