The window for car companies to market semi-solid state batteries may be about to close. According to various media reports, in order to prevent market confusion between solid-state batteries and semi-solid batteries, relevant departments are preparing to issue a new document to rename "semi-solid batteries" as "solid-liquid batteries".

Nowadays, batteries on new energy vehicles, whether they are ternary lithium or lithium iron phosphate, belong to liquid batteries, that is, the electrolyte is in liquid state. Correspondingly, solid-state batteries refer to electrolytes that are solid, while semi-solid batteries have electrolytes that are mostly solid with a small amount in liquid form. The energy density of solid-state battery packs can exceed 500Wh/kg, while liquid batteries that can achieve 200Wh/kg are already considered relatively high. Reflected in new energy vehicles, solid-state batteries can bring longer range, stronger power, and more. I believe that in the past two years, most of you have probably heard news about solid-state batteries. With the endorsement of solid-state batteries, semi-solid state batteries can easily create a sense of extraordinary strength, making them a marketing hot commodity. As early as the end of 2022, Lantu took the lead in the industry by equipping its subsidiary Zhuguang with semi-solid batteries. However, due to the average sales of Chasing Light, semi-solid state batteries have naturally not entered the field of vision of more people. The first company to showcase the power of semi-solid state batteries in front of the public was actually NIO. In December 2023, NIO Chairman Li Bin drove an ET7 equipped with a 150kWh battery pack all the way south from Shanghai to start a live range test. This 150kWh battery pack is a semi-solid state battery released by NIO as early as NIO Day in 2021, with an energy density of 260Wh/kg. When the remaining power of this 150kWh battery pack was 3%, Li Bin had already driven the ET7 for 1044km.

The endurance test has come to an end, and for the first time, the semi-solid state battery has demonstrated its strength in front of over 800000 spectators. However, compared to semi-solid state batteries and information points such as 260Wh/kg, a 150kWh battery capacity is obviously more important for supporting ET7 driving over thousands of kilometers, while high energy density supports more to ensure that the battery volume is not too large, which can then support battery swapping. A noteworthy detail is that NIO President Qin Lihong revealed that the cost of NIO's 150kWh battery pack is equivalent to that of an ET5, indicating the high cost. But NIO's 150kWh battery pack is only available for rent and not for sale, and users actually do not have a high perception of its cost.

What truly makes users perceive the true cost of semi-solid state batteries is actually Zhiji. In May 2024, the Zhiji L6 was launched, with the top configuration equipped with a semi-solid state battery. The CLTC has a range of over 1000km and the price reaches 325900 yuan, which is 40000 yuan more expensive than the second top configuration without a semi-solid state battery. At the same time, due to the marketing of semi-solid state batteries, Liu Tao, co CEO of Zhiji, also engaged in a verbal battle with Zhao Changjiang, General Manager of the Sales Division of Qiantengshi. Although the top configuration of Zhiji L6 is equipped with a semi-solid state battery, both Liu Tao and Zhiji's official promotion claim it to be an "ultra fast charging solid-state battery". Zhao Changjiang then posted on his blog, saying, "At this time, those who promote semi-solid car batteries are playing a word game.

Liu Tao immediately responded, 'Word games are not something we are good at, only technological innovation and iteration can promote the progress of the times.'. Regardless of whether Zhiji has played word games or not, after more than a year of development, its backing SAIC has indeed used technology to once again promote the use of semi-solid state batteries in vehicles, and the gap is still large. On August 29th of this year, the all-new MG4 was launched, and this time the price is even cheaper. The official guide price is 102800 yuan to buy the all-new MG4 semi-solid core version, with a range of 530km and a liquid content of only 5% for the semi-solid battery. In terms of safety, the new MG4's semi-solid battery has successfully passed the 10 needle puncture test and three-way puncture test, and MG has also promised to compensate a new car if the battery ignites spontaneously.

However, it is worth noting that in terms of parameter performance, the new MG4 is equipped with a 53.9kWh semi-solid state battery version, which is no different from the version equipped with a 53.9kWh CATL lithium iron phosphate battery in terms of range, power consumption, charging time, etc. Based on the history of car usage in the past two years, semi-solid state batteries are still in a very primitive exploration stage, and although they claim to be "solid-state", their actual capabilities have not significantly differed from the commonly used liquid state batteries. Although solid-state batteries have not yet been installed in the car, they appear more aggressive than semi-solid batteries and even look like an arms race.

Solid state batteries have made a big breakthrough again

Solid state batteries have recently broken through the biggest bottleneck towards practicality. According to Xinhua News Agency, Chinese scientists have successfully overcome the bottleneck of all solid state batteries. With the same 100kg battery, it used to run up to 500km, but now it is expected to break through 1000km.

At present, the commonly used solid electrolyte for solid-state batteries is sulfide, which has a high hardness, while the metal lithium electrode is relatively soft. So when these two materials are bonded together, the interface is always bumpy, which greatly affects the efficiency of lithium ion movement between the positive and negative electrodes. After some research, the Institute of Physics of the Chinese Academy of Sciences, together with several scientific research teams, found that iodine ions can attract lithium ions at the interface, filling up the potholes, thus ensuring the mobility efficiency of lithium ions between the positive and negative poles. At the same time, the Institute of Metals of the Chinese Academy of Sciences has also used polymeric materials to keep the battery intact even if it is bent 20000 times and twisted into a Fried Dough Twists shape; The research team at Tsinghua University has modified the electrolyte with fluorinated polyether materials, which can prevent high-voltage breakdown of the electrolyte and further ensure battery safety.

Of course, the light boat is still far from passing through Mount Wanzhong. From the laboratory to mass production in the factory, there are still many difficulties to overcome, such as technological development, improvement of supporting supply chains, adjustment of production lines, and improvement of yield rates, which is equivalent to a revolution in power battery production. In addition, some car companies have recently disclosed the latest developments in solid-state batteries. Toyota announced earlier this month that it will launch all solid state batteries in 2027-2028. This means that if Toyota hadn't made a big picture, the first mass-produced car equipped with all solid state batteries would be less than two years away from now.

However, those familiar with the plot may still remember that Toyota had previously written the year 2026, which has now been quietly postponed. In addition, Mercedes Benz used an EQS test car equipped with a solid-state battery in September, and traveled a total of 1205km across three European countries without charging, passing through different climates and road conditions. Although the car is a test car and the solid-state battery is not in mass production, the results themselves show that the imagination space brought by solid-state batteries is still very beautiful. But imagination is always easy to imagine, whether the future reality can be satisfactory or not, there is still a big question mark to be raised now. The Chairman of CATL, Zeng Yuqun, once said, "If we use numbers 1 to 9 to indicate the technology and manufacturing maturity of solid-state batteries, the current industry's highest level is only around 4, and only some device samples have been made for experimental verification." We have also summarized a schedule of solid-state batteries for major car companies, and you can also guess in the comment section which car companies can "submit their work" on time.

Both semi-solid state batteries and solid-state batteries are still in the early stages of development. In the past two years, solid-state batteries have almost undergone a "god making movement", as if all the problems encountered by power batteries can be easily solved once solid-state batteries are mass-produced and put on the car, and they can rest assured from then on. Due to the halo effect of solid-state batteries, semi-solid state batteries have also gained popularity in the market and have already achieved initial mass production on vehicles. However, in practical applications, although semi-solid batteries sound very similar to solid-state batteries, their overall strength still has a considerable gap compared to solid-state batteries, so it is difficult to compare them. Therefore, if semi-solid batteries are really renamed as "solid-liquid batteries", it is indeed a good thing to regulate market competition and prevent users from being misled by the "concept".