On December 17, Li Bin, chairman of NIO, personally tested the 1,000-mile endurance of the semi-solid-state battery pack loaded on the ET7 smart pure electric vehicle after 14 hours in the cold winter, and conducted a live broadcast, which caused a lot of heated discussions.
Self-developed 150 semi-solid-state battery pack: hard-won
In this live broadcast, Li Bin drove the NIO ET7 equipped with a 150kWh battery pack, with an energy density of 360Wh kg per cell and a measured range of 1044 kilometers. This is also the first public live test of a semi-solid-state battery model.
The battery tested was first launched on NIO Day on January 9, 2021, and uses a solid-liquid hybrid electrolyte, which is a semi-solid-state battery.
Among the domestic new energy vehicle companies, NIO has always been very enthusiastic about power batteries. And this battery pack, which has been jointly developed by NIO and Weilan New Energy for three years, is really hard-won.
The difficulty of developing batteries is much greater than NIO imagined, and it has encountered difficulties in both production lines and technology, coupled with the high cost of developing batteries, resulting in self-developed batteries becoming a heavy burden for NIO.
According to the financial report data for the second quarter of this year, NIO's R&D expenditure in a single quarter was as high as 33400 million yuan, R&D expenditure exceeded 3 billion yuan for the third consecutive quarter, and on the other side of high R&D investment, NIO's net loss in a single quarter increased by 278%, up to 60$5.6 billion. As a result, NIO has had to slow down its plans for new cars in the future and start rolling out more sales resources.
Why develop semi-solid-state batteries
Solid-state batteries refer to lithium-ion batteries with solid-state electrolytes, which are safer than lithium iron phosphate and have greater energy density than ternary batteries, but they have not yet been mass-produced due to immature material application and technology, high cost and other problems. Semi-solid-state batteries with high safety, long life and economy have become a compromise.
"Range anxiety" is an unavoidable topic in the field of new energy vehicles, and it is also constantly promoting the continuous improvement of battery energy density. The chemical system of the cathode and anode materials determines the upper limit of the energy density of the cell, and the solid electrolyte has higher safety and a wider voltage window than the electrolyte.
However, at present, due to some technical difficulties of all-solid-state batteries, semi-solid-state batteries have little change to the existing liquid lithium-ion battery system, and are regarded as products for the transition to all-solid-state batteries. Many new energy vehicle companies such as Weilai, Cialis, Changan Deep Blue, and VOYAH continue to disclose the progress of semi-solid-state battery installation, and they are also eager to try the installation of semi-solid-state batteries, which continues to stimulate the acceleration of upstream power battery manufacturers in research and development.
How it performs
In this live test, Li Bin drove the ET7 equipped with a 150-degree semi-solid-state battery from Shanghai all the way to Longdudong, the lowest weather along the way was -2 degrees Celsius, the highest was 12 degrees Celsius, the temperature difference was more than 10 degrees Celsius, and the average cabin temperature was 20 degrees Celsius, that is to say, the journey of more than ten hours was fully heated and air-conditioned, and the load on the car was 190kg, which is the weight of two adults. Under the above conditions, the final mileage is 1044 kilometers, and the comprehensive energy consumption of 100 kilometers is about 13Excellent results of 2 degrees.
So what is the most critical average speed?83.9km/h。In June this year, the ZEEKR 001 1,000-mile endurance kit equipped with CATL Kirin batteries was delivered to Zeng Yuqun, chairman of CATL, with a battery pack capacity of 140 degrees, a CLTC comprehensive working range of 1032 kilometers, and an average speed of only 41km h.
In May, some riders measured the car in Qinghai under the condition of air conditioning of 23 degrees Celsius, and the cruising range was 9229 km, average speed 79 km/h, energy consumption 147 degrees 100 km.
Judging from the industry trend, large-capacity battery packs will inevitably be gradually replaced into the market. In April '21, Mercedes-Benz's EQS battery pack capacity was 1118. The cruising range under the highest working condition is 849 kilometers. In November of the same year, GAC Aion released the LX Plus, which had a battery pack capacity of 1444 degrees, the cruising range in working conditions reaches 1008 kilometers.
However, compared with the liquid electrolyte lithium-ion cells used in the above large-capacity battery packs, the special feature of the battery pack tested by NIO this time is that it uses semi-solid electrolyte cells. According to the information released by NIO in 2020, the battery uses a solid-liquid electrolyte cured in situ, an inorganic pre-lithiated silicon carbon anode, and an ultra-high nickel cathode coated at the nanometer level.
According to the previously disclosed data, although the battery cells of this battery were jointly developed by Weilai and Weilan New Energy, the battery pack was completely self-developed by Weilai, which took a total of 3 years before and after, with a team of more than 300 people, and the proportion of master's and doctoral degrees in the team accounted for 17% and 16% respectively.
The advantages and disadvantages are in the **?
In addition to NIO, many companies in the domestic new energy vehicle industry chain are also actively conducting technology research and development on semi-solid-state batteries.
Judging from the loading progress, on November 8, the semi-solid-state battery of Funeng Technology was loaded off the assembly line in the first batch of Yuanhang Y6;The Seres5 is equipped with Ganfeng Lithium's first-generation solid-state battery with an energy density of 260Wh kg, and the first batch of deliveries has been achieved in June this year. In addition, SAIC, Changan, GAC, BAIC and other car companies have also launched semi-solid-state battery loading plans. Among them, SAIC Zhiji will install Qingtao Energy's semi-solid-state batteries in 2024The BAIC Group invested in Qingtao Energy in 2019 and plans to equip its new vehicles with a 400 Wh kg solid-state battery by 2025.
It is worth noting that every change in the battery technology route will bring about the update of raw materials. The semi-solid-state route has little change in the existing liquid lithium-ion battery system, and there are differences in the route selection of solid-state battery companies in the primary market such as Weilan and Qingtao and power enterprises such as Funeng Technology, Guoxuan Hi-Tech, and Honeycomb Energy.
NIO's biggest advantage lies in its concept, which is "rechargeable, swappable and upgradeable". Although many people believe that the range of NIO is not strong, for example, the range of the original ES6 released in 19 is only 420 kilometers, which is really not enough for today's consumers. However, after NIO released the 100-degree battery, it can achieve ES6 600 km+ range by upgrading a large battery at the battery swap station. It is not difficult to perceive from the existing past that today's NIO ET7 can also do a good job of battery life, after all, the new battery and old cars can also be used.
The downside is that at the moment, it may be the cost. At a face-to-face event for users, Qin Lihong, president of NIO, revealed, "The cost of a 150 kWh battery is very high, and the cost is equivalent to that of an ET5 (75kWh battery version of the vehicle 32.).80,000 yuan, lease 2580,000 yuan). ”
Finally
Endurance is a long-lasting topic in the new energy vehicle industry, and the R&D breakthrough of semi-solid-state batteries has made an important step forward in the development of the industry, but the emergence of new products is always worth long-term observation.
In general, NIO's public live broadcast of the 150-degree semi-solid-state battery test at least shows that it has the ability to mass production. In addition, it is worth noting that affected by this news, the share price of power battery giant CATL declined, and the capital market silently voted for the development trend of the power battery market.