The rhythm of ternary lithium batteries replaced by solid-state batteries is getting faster. Why do you say this? Shenzhen lithium battery manufacturers will take you to see the news announced by Ningbo Institute of Materials Technology and Engineering of the Chinese Academy of Sciences today:

The nano-lead special "all solid-state battery" project led by the company has passed the acceptance test. This technological advancement will further promote the scale application of domestic all-solid lithium battery.

As soon as this news came out, it immediately caused a huge response in the battery industry.

According to industry insiders : "With the current technical route of ternary lithium battery, the goal of 350Wh/kg for power battery energy density monomer is basically impossible in five years. Moreover, even if it is realized, security cannot be obtained. Guarantee. Therefore, whether the commercialization of solid-state batteries can break through, has a significant impact on the prospect of automotive electrification."

As the core of electric vehicles, the breakthrough in the battery field will undoubtedly have a major impact on the development of batteries and even the automotive field. So, can solid-state batteries immediately replace ternary lithium batteries? How far is it from marketization?

Natural defects of ternary lithium batteries: energy density and stability are contradictory

“A single company had 60 electric vehicle combustion explosions last year.” At the China-Japan-Korea Lithium Forum, the director of the New Energy Materials and Technology Laboratory of Peking University revealed that Professor Lu.

His professor believes that there are many defects in the ternary lithium battery, and the safety issue is very worrying. “In terms of chemical structure and battery structure, ternary materials are very prone to heat. If the heat cannot be conducted in time, the battery will have an explosion risk. However, at this stage, the safety and reliability of the battery. There is still no perfect solution."

In addition to safety issues, in terms of increasing the battery life angle, the single-element energy density of the ternary lithium battery is near the limit and is difficult to break through. Zhou Nan, executive vice president of battery pack supplier, said : "Now, no matter the industry policy or market demand, the energy demand of power batteries for new energy vehicles is very high. Under the current technology system, To increase the energy density, only nickel materials or CA can be added, but the thermal stability of high nickel is very poor. Therefore, once the energy density of a conventional battery is increased, it means that the stability is lowered, and the internal thermal reaction of the battery is very intense. Security is a big problem."

For this reason, Xiao Chengwei, an expert of the “863” plan for energy conservation and new energy vehicle major projects, has publicly stated that the ternary lithium-ion battery has seen the “ceiling” of energy density, high nickel material, carbon silicon. The lithium battery cell of the negative electrode should have a higher energy density of about 300 Wh/kg, and the positive and negative do not exceed 20 Wh/kg.

According to the plan of the power battery technology roadmap, the single-energy density target of lithium-ion batteries in 2020 is 350Wh/kg. From the current point of view, this goal has not been achieved.

In order to ensure the high energy density and safety of the power battery, the development of solid-state battery development has brought light and light to the industry.

Domestic and foreign companies compete for layout, solid-state battery trends

A solid state battery, as the name implies, is a battery that uses a solid electrode and a solid electrolyte. Since the solid battery electrode and electrolyte are made of solid materials, the solid electrolyte is non-flammable, non-corrosive, non-volatile, and liquid-free, and also overcomes the phenomenon of lithium dendrite. Even if it is heated to a very high temperature, it will not It is on fire and thus safer. For vehicles equipped with all-solid-state lithium batteries, the probability of spontaneous combustion will be greatly reduced. It can be said that it is the ideal target for the next generation of new energy vehicle power batteries.

At present, more and more domestic and foreign companies and research institutions have focused on all-solid-state lithium batteries, and many automakers have revealed plans to build electric vehicles based on solid-state batteries. For example, Volkswagen has announced plans to develop a 1000km solid-state battery; Toyota is expected to complete the development of solid-state batteries in 2022, and plans to achieve mass production in 2030; the Ministry of Economy and Economy announced that it will contribute 1.6 billion yen in 2017, in conjunction with Toyota Honda, Nissan, Panasonic, GS Tangshao, Dongli, Asahi Kasei, Mitsui Chemicals, Mitsubishi Chemical and other domestic industrial chain forces to jointly develop solid-state batteries, and hope to achieve the 800-kilometer endurance target in 2030.

Academician Ouyang Minggao, the chief expert of key technologies for new energy vehicles, also pointed out that many domestic research institutes and enterprises have deployed solid-state batteries. The Ningbo Institute of Materials Science and Technology of the Chinese Academy of Sciences is cooperating with Yanfeng Lithium Industry to promote its industrialization. Produce solid state batteries.

As the "heart" of new energy vehicles , power batteries will undoubtedly determine the future of new energy vehicles. It is widely believed in the industry that the future development path of power batteries is that the electrolytes are mixed from liquid, semi-solid, solid-liquid to solid, and the process of solid-state will be realized. This has prompted a new round of investment and research in battery technology by well-known companies such as startups, universities and Tesla.

Toyota's timetable is relatively reliable, and solid-state battery production may have to wait until 2030.

However, solid-state batteries need to solve multiple problems in order to further develop.

Zhou Nan said : "Solid electrolyte is the key to the development of solid-state batteries. Solid-state batteries do not have liquid infiltration. They do not need a separator. They only use solid electrolytes as separators and are placed in positive and negative pole pieces. Materials are especially critical."

Electrolyte materials are the core of all-solid-state lithium battery technology. At present, the research of solid electrolytes mainly focuses on three types of materials: polymers, oxides and sulfides. The high temperature performance of the polymer is good, and there are already commercial application cases; the oxidation cycle performance is good, and it is suitable for the flexible structure of the film; the conductivity of the sulfide is higher , which is the main direction in the future.

However, there are still several specific challenges that need to be overcome:

First, the conductivity of the interface, the conductivity of the solid state battery should be maintained at an appropriate level, not too high, nor too low, such materials are very difficult to develop.

Second, there is no composite material that can be considered both high-rate and fast-charged. The solid electrolyte materials used now can only accommodate one of the characteristics.

An industry insider who did not want to be named also expressed the same view. He believes: "The solid electrolyte has high electrical resistance, and there are still some problems to be solved in terms of power density. It needs to start from solid electrolytes and positive and negative materials. Conductivity, battery rate, battery preparation efficiency, and cost control are all present. No small challenge, once these problems can be effectively solved, it will definitely set off a new battery revolution in the future."

Since there are many difficulties, how long does it take for solid-state batteries to be fully utilized in new energy vehicles?

Ouyang Minggao said that it is expected that all solid-state lithium batteries will make a breakthrough between 2025-2030. In May of this year, Shinzuo Abe, general manager of Toyota Powertrain Division, said: "Toyota expects to manufacture solid-state batteries after 2020, but to achieve mass production of solid-state batteries, it will have to wait until 2030."

Zhou Nan, who has been deeply involved in the battery industry for more than ten years, said frankly: "From the experience of the past, the Toyota plan and the actual situation are basically the same. Perhaps in the past few years, they have been able to introduce solid-state batteries. But what is the specific capacity, the cost can not adapt to the market, but also a big question mark."