Can solid-state batteries be able to burn lithium batteries?

In recent days, solid-state batteries have become a hot topic in the battery industry. The source is that a few days ago, the US company Fisker Motors released a new battery technology - solid-state battery, said to increase the mileage of electric car users to 500 miles (about 804 km) or more, charging time is only 1 minute . There is even a view that solid-state batteries can "finish seconds" lithium batteries. Multinational car companies are getting faster and faster in the field of solid-state batteries. This is not the first news about the development of solid-state batteries.

To what extent is solid-state battery now developed? Is the performance as such as the outside world so superior? How far is it from commercialization? In this regard, the reporter interviewed relevant experts to understand:

Two distinctive features of solid-state batteries

First, the energy density is about 2.5 to 3 times that of a conventional lithium battery;

Second, it is safer and eliminates the burning hazard caused by accidents such as battery rupture or high temperature.

Two difficulties in solid-state batteries

One is the problem of the electrolyte material itself;

The second is the regulation and optimization of interface performance. From the current point of view, its commercialization path is still very long.

Foreign solid-state battery results frequently

Recently, a number of new solid-state battery trends have attracted the attention of the industry. According to foreign media reports, Fisker has applied for a solid-state battery patent and is expected to achieve mass production in 2023. Fisker claims that Fisker's solid-state battery uses a three-dimensional electrode with an energy density 2.5 times that of a conventional lithium-ion battery.

Not only does Fisker expose solid-state battery news, but many companies and organizations around the world have also released the latest developments in solid-state batteries. According to "Global Solid State Battery Market 2017 ~ 2021", at present, Toyota, Panasonic, Samsung, Mitsubishi, BMW, Hyundai, Dyson and other companies are stepping up the development of reserve solid-state batteries. Bolloré of France, Sakti3 of the United States and Toyota of Japan represent the technical development direction of the three solid electrolytes of polymers, oxides and sulfides, respectively. In addition, there are reports showing:

1. The French company Borole has invested 2,900 electric vehicles equipped with 30kWh metal lithium polymer batteries (LMP) produced by its subsidiary Batscap;

Second, Toyota developed an all-solid-state lithium-ion battery with an energy density of 400Wh/L. Toyota researchers said that the battery will be commercialized around 2020;

Third, Panasonic's latest solid-state battery energy density has increased by 3 to 4 times; Honda and Hitachi Shipbuilding has established an Ah-class battery, which is expected to be mass-produced in three years.

For research and development, some foreign companies have developed independently in the field of solid-state batteries, while others have chosen joint research and development. For example, Volkswagen is relatively late in the development of solid-state batteries, but is prepared to develop it on its own. Not long ago, Toyota announced that it has cooperated with Matsushita to develop solid-state batteries. A few days later, BMW announced that it has cooperated with SolidPower to develop solid-state lithium batteries. Bosch and the famous Japanese GSYUASA (Tangshhao) Battery Company and Mitsubishi Heavy Industries have jointly established a new factory, focusing on solid-state anode lithium-ion batteries.

Domestically tightened research and development of solid-state batteries

In China, the Chinese Academy of Sciences (hereinafter referred to as "Chinese Academy of Sciences") has a relatively early layout on solid-state batteries. Currently, five R&D teams have made different progress.

1. The team of Guo Yuguo of the Institute of Chemistry of the Chinese Academy of Sciences developed a polyether-acrylate polymer solid electrolyte with an oxidation resistance of 4.5 volts.

2. The Xu Xiaoxiong team of the Ningbo Institute of Materials of the Chinese Academy of Sciences developed oxides, sulfide solid electrolyte materials, ceramic sheets, and all-solid-state batteries, and tried to industrialize with the company. At present, the team has taken the lead in developing a series of solid-state single cells with a capacity of 0.2Ah~10Ah. The energy density of 10Ah solid-state single cells reaches 260Wh/kg, and the capacity retention rate of 1000 cycles is 88%.

3. Cui Guanglei from the Qingdao Institute of Bioenergy of the Chinese Academy of Sciences developed a solid electrolyte of polypropylene carbonate, cellulose, lithium lanthanum zirconium oxide. The energy density of the developed battery reached 300Wh/kg, and completed the deep sea for the first time in the Mariana Trench test.

4. Guo Xiangxin, team of Shanghai Institute of Ceramics, Chinese Academy of Sciences, developed a solid electrolyte of polyethylene oxide, lithium lanthanum zirconium oxide, and developed a 2Ah solid lithium ion battery.

V. The Institute of Physics of the Chinese Academy of Sciences proposed and verified the concept of in-situ solidification. The energy density of the 10Ah soft-packaged cell reached 310-390Wh/kg, and the volumetric energy density reached 800-890Wh/L. The battery can be at room temperature 90. Circulate at °C.

In addition, the famous domestic battery company Ningde era has also invested in the research and development of solid-state batteries. At present, the polymer lithium metal solid battery cycle in Ningde era has reached more than 300 weeks, and the capacity retention rate has reached 82%.

Commercialization still needs to overcome many shortcomings

Nowadays, the development of solid-state batteries is in full swing. In the long run, what kind of development will it show? An authoritative expert on solid-state batteries told the China Automotive News that the development of solid-state batteries mainly follows two routes: one is the polymer route; the other is the all-inorganic ceramic route, and the all-inorganic ceramic route can be divided into oxides and sulfides directions. At present, both technical routes have insurmountable shortcomings and cannot be commercialized on a large scale.

Ceramic route solid state battery

The biggest problem of the ceramic route solid-state battery is that the energy density is relatively low, similar to the lithium titanate battery in the existing battery, which has lower energy than the lithium iron phosphate and the ternary material battery, but can be charged and discharged at a large rate. The relatively low energy density makes ceramic-lined solid-state batteries less economical than existing batteries. The expert told reporters that Japan has been on the ceramic route solid-state battery for more than 10 years and has a leading edge. The 15-minute full of electricity proposed in the Japanese propaganda report is completely credible.

Polymer solid state battery

Polymer solid-state batteries have higher energy densities but lower charge rates according to reports the internal resistance between the polymers solid-state battery interface is large, and it takes more than 5 hours to fully charge. It is also because of the high energy density that fast charging can be dangerous. Due to the large internal resistance, polymer solid-state batteries cause energy loss during charging, which is a problem that cannot be ignored. In addition, the most deadly problem with polymer solid-state batteries is the high charging temperature and low charging rate at room temperature, which limits large-scale commercial applications. However, most of the research institutions and enterprises in China are currently targeting polymer solid-state batteries.

From the perspective of the development of global solid-state battery technology, China is not backward, and it is comparable to foreign advanced technology. Cui Guanglei, a researcher at the Qingdao Institute of Bioenergy, Chinese Academy of Sciences, told reporters that the solid-state battery developed by the team he led successfully carried out the “Qingeng-1” full-deep sea power application demonstration in the Mariana Trench, making China the second master of the whole sea after Japan the country of lithium power technology.

Ouyang Ming, a member of the Chinese Academy of Sciences and a professor at Tsinghua University, also spoke of the development of solid-state batteries. He said:

The United States focuses on the development of large-capacity solid-state lithium batteries for organic-inorganic composite solid electrolytes, with small companies and entrepreneurial companies. Both Japan and South Korea have developed large-capacity solid-state lithium batteries using inorganic solid electrolytes, and several companies have introduced mass production plans. The situation in China, Japan and South Korea is similar. Three countries already have large lithium-ion battery industry chains and do not want to reinvent themselves.

In general, the development of solid-state batteries, electrolytes may follow the path from liquid, semi-solid, solid-liquid mixed to solid state development, and finally to all solid state. In the case of the negative electrode, the transition from the graphite negative electrode to the silicon carbon negative electrode. At present, China is transforming from graphite anode to silicon carbon anode, and finally it is possible to turn to lithium metal anode. However, there are technical uncertainties in this route.

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