Can the all-solid-state battery, which will be mass-produced in two years, solve the current range anxiety?

AutoLab

2024-05-26 20:53Posted on Shanghai AutoLab official account

In March, Liu Tao, CEO of Zhiji Automobile, said on Weibo that the Zhiji L6 will be equipped with the first mass-produced ultra-fast charging solid-state battery, which caused a lot of heated discussions at the time.

In the end, the price of the Zhiji L6 light-year version equipped with solid-state batteries came to 345,900, which is 20,000 yuan more expensive than the sub-top super performance version and 70,000 yuan more expensive than the ultra-long endurance version that can run 850 kilometers under CLTC conditions.

Although a lot of the content that everyone is talking about is "white horses and non-horses", consumers are still quite concerned about the development of solid-state batteries.

After all, compared with traditional lithium batteries, solid-state batteries have high energy density and good safety, which is a combination of fish and bear's paws, which is very in line with the consumption psychology that everyone wants and wants.

Regarding the development of solid-state batteries, at the "New Energy Technology Conference" held by SAIC, SAIC once again stated that in 2026, all-solid-state batteries will be delivered to mass production and sample tests will be completed, and the energy density of the battery cells will exceed 400Wh/kg.

So, can the all-solid-state battery, which will be mass-produced in two years, solve the current range anxiety?

What's so good about solid-state batteries?

However, before the arrival of all-solid-state batteries, let's talk specifically about what is good about solid-state batteries?

The first is security.

We know that there are many challenges in traditional lithium batteries, such as high-power charging can easily cause lithium separation in the battery, which affects the battery life, in addition to battery thermal runaway, thermal management and other problems.

The common acupuncture test is aimed at the challenges of thermal management of traditional lithium batteries.

Because the acupuncture test pierced the cell separator, it was artificially caused by a short circuit between the positive and negative electrodes inside the battery.

After a short circuit, the lithium-ion battery will generate a large current through the short circuit point, and the high current will bring a very high temperature, which will lead to thermal runaway and fire and explosion.

But for solid-state batteries, none of this is a problem.

First of all, due to the different electrolyte formulations, solid-state batteries do not have to worry about lithium separation from the battery at all, and the solid-state electrolyte itself can inhibit the growth of lithium dendrites.

Secondly, regarding the thermal management of the battery, the traditional liquid lithium battery is more susceptible to thermal runaway, for example, at 90°C, the SEI film on the surface of the negative electrode of the battery will decompose, and then the separator will melt, forming an internal short circuit.

When the cell temperature rises to 200°C, the electrolyte can be directly vaporized, causing the battery to burn violently and explode.

In general, solid-state batteries have low flammability due to the absence of liquid substances or a significant reduction in liquid substances, and their thermal stability is much higher than that of liquid electrolytes.

The most buggy thing is that not only is it resistant to high temperatures, but solid-state batteries are actually more resistant to low temperatures.

Conventional liquid lithium-ion batteries will increase the viscosity of the electrolyte due to low temperature, which will reduce the conductivity, increase the electrolyte/electrode interface impedance, and the charge transfer impedance, including the lithium ion migration rate, which will eventually lead to the degradation of battery charging and discharging performance.

However, in solid-state electrolyte batteries, there is no problem of electrolyte solidification due to low temperature, because the electrolyte itself is solid-state.

Of course, there is also an interface impedance problem that needs to be solved in the current solid-state electrolyte, after all, the contact degree of the solid-state electrolyte is still not as good as that of the liquid electrolyte, but the influence of low temperature is not obvious.

At present, the reason why there are semi-solid-state batteries is because there is an impedance problem at the interface of the solid-state electrolyte, and in order to increase the interface contact, a part of the infiltrated liquid is added to the electrolyte, so there are semi-solid-state batteries.

Crucially, solid-state batteries also have the advantage of high energy density.

This is also because the chemical properties of the solid-state electrolyte in solid-state batteries are relatively stable, unlike high-energy electrode materials such as lithium metal, which are incompatible with organic electrolytes, but solid-state electrolytes can increase the energy density of the battery by adapting high-energy cathodes and lithium metal anodes.

The "light-year solid-state battery" on the Zhiji L6 mentioned at the beginning is actually the first generation of SAIC Qingtao's solid-state battery, and the energy density of this battery also exceeds 300Wh/kg. At present, the theoretical limit of energy density of traditional liquid lithium batteries is 350Wh/kg.

In terms of energy density, the current semi-solid-state batteries exceed the level of CATL Kirin batteries (255Wh/kg).

Suffice it to say, there is a lot of potential.

At this stage, is it more or lower?

Not only are they high energy density and safer, but solid-state batteries also have the benefit of lower cost.

At present, solid-state batteries are based on the simplification and innovation of materials and processes, and the unit cost of solid-state batteries can be reduced by up to 40% compared with liquid lithium batteries from the cell end to the pack end.

For example, on the most obvious cell package.

At the SAIC technology conference, AutoLab also interviewed the staff of SAIC Qingtao Energy about why the solid-state battery chooses pouch packaging, and the reply is as follows:

Compared with prismatic and cylindrical batteries with steel and aluminum shells, pouch batteries with aluminum-plastic membrane shells will reduce a lot of costs in terms of materials, and also improve the lightweight and energy density of the battery.

Of course, for us consumers, since the cost of solid-state batteries has decreased, has the cost of buying a car also decreased?

The answer, of course, is yes.

However, it is only because the semi-solid state has just begun to appear, and the technology is still in the process of development, so it is not a good time for large-scale production of battery factories, and car companies have not yet launched large-scale cars.

As a result, the current cost of semi-solid-state batteries is extremely high, and naturally it cannot be compared with the cost of all-solid-state large-scale mass production in the future.

For example, the semi-solid-state pouch battery cell jointly developed by NIO ET7 and Weilan New Energy has an energy density of up to 360Wh/kg per cell, and the cost of a semi-solid-state battery with 140 kWh of electricity is said to be the price of an ET5.

We also interviewed an engineer at SAIC who said that users' all-electric range anxiety will have a marginal effect after the nominal range exceeds 700 kilometers. Therefore, it is unrealistic to make consumers pay for such an expensive solid-state battery at this stage.

Around 2027, solid-state battery models will be unveiled

Far water can't quench the thirst of the near, when will the all-solid-state battery with lower price and higher energy density after large-scale mass production in the future come?

The general expectation in the industry is to achieve mass production of solid-state batteries with all-solid-state electrolytes around 2027.

For example, at this SAIC press conference, the plan for solid-state batteries to achieve mass production in 2026 is planned.

In fact, there is a slight difference compared with last year's announced solid-state battery plan of Qingtao Energy, because last year's goal of Qingtao Energy is to achieve mass production of all-solid-state batteries with an energy density of more than 500Wh/kg in 2027.

It may be because the current involution of the new energy market is too fierce, even in the field of solid-state batteries, everyone is competing for the position of the first brother.

After all, whoever can mass produce a new technology earlier will have a better chance of capturing the minds of users, and it is still very important for new power brands with shallow foundations.

However, it may also be because of the advance mass production time, the energy density index of its all-solid-state battery has also dropped from more than 500Wh/kg to more than 400Wh/kg.

However, in 2027, SAIC's new Zhiji car equipped with an all-solid-state battery will be mass-produced, and the energy density is expected to be further increased to 500Wh/kg in the future.

In fact, it can be seen that around 2027, according to the plans of each company, there will be more car companies with solid-state batteries for trial installation or mass production.

For example, BYD, Changan Deep Blue, GAC Haobo, BMW, Volkswagen, Nissan, Toyota, Hyundai and so on.

This time period will also be a period when models equipped with all-solid-state batteries will be unveiled, and on the whole, the mass production of all-solid-state batteries by domestic car companies is still earlier.

At that time, in the new energy vehicle market, due to the addition of the new technology of all-solid-state batteries, as well as the first mover of domestic car companies, it is foreseeable that a new round of fierce involution in the automobile market will be inevitable.

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