As we all know, the power battery, which is known as the "heart" of new energy vehicles, any breakthrough in technology will have an impact on the performance of electric vehicles. I believe that every automotive industry practitioner and consumer knows this. However, under the general trend of the rapid development of the global new energy vehicle market, the evolution and update speed of battery technology seem to be unable to keep up with the pace of the market. As a result, the world's major automobile manufacturers, battery companies, and even scientific research teams are seeking breakthroughs and even changes in power battery technology through their own ways. So in the past 2021, what breakthroughs have been made in power battery technology?
The first cobalt-free battery off the production line, electric vehicles are afraid that the cold winter will become a thing of the past?
In the field of electric vehicles, the biggest test facing the power battery is the endurance problem, which will be more obvious in the cold and extreme weather in the north, the battery activity will be reduced, and the endurance will be greatly reduced. As a result, almost all car companies hope to seek a breakthrough in mileage.
After five years of technical research, GAC Aeon took the lead in developing sponge silicon anode chip battery technology, which can reduce the volume of lithium-ion battery cells by 20% and weight by 14%. While increasing the energy density of the battery, it can also reduce the weight of the battery. More importantly, the power battery equipped with sponge silicon anode chip battery technology has been installed on the newly launched AION LX Plus model of GAC Aeon, and the CLTC has reached 1008 kilometers of endurance. This achievement also makes it the first model to be "certified" by the Ministry of Industry and Information Technology for pure electric endurance of more than 1000KM.
Also completing the landing of new technologies is Great Wall Motor's Hive Energy, which announced on July 16, 2021 that the world's first cobalt-free battery was officially mass-produced and applied to the Cherry Cat model of Great Wall Euler, and it is believed that it will be gradually installed in more new energy models under the Great Wall in the future. According to the introduction of honeycomb energy, the energy density of the cobalt-free battery produced in this mass production reaches 240Wh/kg, the capacity is 115Ah-MEB, the energy density is very high, and the energy density of the industry's current ternary lithium battery pack is at the level of 160-190Wh/kg. Such a high-density power battery also means that pure electric cars will have a longer cruising range, even if there is endurance attenuation in the cold winter, it will not have much impact.
Of course, whether the battery technology is advanced not only depends on the energy density, but also depends on its cost and safety, in this regard, the life of this cobalt-free battery cell is longer than the same level of high-nickel ternary battery, the cell cycle life of more than 3000 times, can easily pass the 150 ° C hot box test and 140% SOC overcharge test, and passed the GB/IEC62660/UL2580 and other standard certifications.
Sodium ion batteries arrows on the string, cheaper trams are coming?
In 2021, the development of power batteries is still rapid, there are new technology batteries that have landed, and there are also new power batteries that are about to go offline and the arrow is already on the string. Among them, the new product released by Musk before , the 4680 battery , has also made new progress. In a previous report, Tesla posted a video of the 4680's new battery and its production line on social media, and said that this production line will be used in gigafactories in Texas and Berlin, which further indicates that the 4680 battery is about to roll off the production line.
Compared with the current 21700 battery, Tesla's 4680 battery is made of laser engraving electrodeless ear technology, which increases the energy by 5 times and the power capacity by 6 times. When applied to Tesla vehicles, it can increase mileage by 16% and reduce cost per kilowatt-hour by 14%. In addition, the 4680 battery also has a higher energy density advantage, due to the high matching between the 4680 cylindrical cell and the silicon-based negative electrode, so the specific capacity of the silicon-based negative electrode is higher than the graphite anode, so it is easier to make the battery per volume carry more power, thereby improving the vehicle's cruising range. However, due to the high production cost, the future 4680 battery may only be one of the mainstream batteries of luxury electric vehicles.
In 2021, another power battery blockbuster news is the battery industry "giant" - Ningde times officially released the first generation of sodium-ion battery products, according to our understanding before, the cell energy density of the sodium-ion battery displayed this time reached 160Wh/kg; charging at room temperature for 15 minutes, the power can reach 80%; -20 °C low temperature environment, can maintain more than 90% of the battery efficiency and other characteristics. More importantly, the production cost of sodium-ion batteries is relatively low, and the acquisition of sodium is easier than lithium, so it is of positive significance to expand the scale of production capacity or reduce vehicle costs.
Of course, the disadvantages of sodium-ion batteries are also very obvious, compared with lithium-ion batteries, sodium-ion energy density is relatively lower, the current sodium-ion battery cell monomer energy density general value is 120Wh/kg, which is much lower than the 240Wh/kg of ternary lithium batteries and 180Wh/kg of lithium iron phosphate batteries. At the same time, the number of sodium-ion batteries is very small, and the highest number of universal cycles is only 1500 times, which is almost not in an order of magnitude compared with the 6000 times of lithium iron phosphate batteries and 3000 times of ternary lithium batteries.
In response to these disadvantages, CATL launched the "AB battery solution", specifically the sodium-ion battery and the lithium-ion battery are integrated in the same set of battery systems at the same time, and then rearranged to form a mix-and-match, series, parallel, integration, and subsequent balanced control of different batteries through BMS, which looks a bit complicated. However, after a series of research and development, the Ningde era has made a breakthrough, declaring that the energy density of the next generation of sodium-ion batteries will exceed 200Wh/kg, as for when it will land, when the first model can carry sodium-ion batteries, it may take a while.
Bipolar batteries / lithium-sulfur batteries / lithium metal batteries, which PPT battery is stronger?
In the new runway of power batteries, major companies around the world are injecting a lot of manpower and financial resources into their research, and there are no small breakthroughs in power batteries in overseas markets, but unlike us, some of these technological breakthroughs are still in the primary stage of the laboratory. For example, in 2021, Germany's ThyssenKrupp and Daimler are developing bipolar batteries for electric vehicles based on lithium-ion technology, a battery project called EMBATT-goes-FAB, which is said to be optimized to enable electric vehicles to reach a maximum range of 1,000 kilometers, which can effectively solve the current problem of endurance anxiety and insufficient battery life.
The Mercedes we know as well is also experimenting with power batteries, but it's developed in a different way, and on the concept Mercedes EQXX, it just redesigned the battery pack to have more than twice as much power in a smaller space than the production car, which is a bit like a combination of LEGO bricks. The advantage is that in the event of a single cell failure, simply pull out one of the modules and replace it easily.
In the laboratory of the University of Michigan in the United States, researchers claim to have updated a related technology, that is, lithium-sulfur batteries. The main reason is that lithium-sulfur batteries can store more energy, but because of their limited number of charge and discharge cycles, they cannot work better. The researchers came up with the idea of using aramid nanofibers recovered from Kevlar (the material that makes bulletproof vests), which not only increases the number of cycles of charge and discharge, but also increases the endurance of lithium-sulfur batteries by five times, and can also have the ability to use normally in extreme environments. However, after leaving the laboratory, the cycle life of this battery in the actual environment may be shortened by fast charging, and it will only have a lifespan of about ten years.
It is worth mentioning that in the "Top Ten Breakthrough Technologies in the World" released by MIT Technology Review 2021, Silicon Valley startup QuantumScape developed a new lithium metal battery that was successfully shortlisted and awarded, which triggered a hot discussion in the industry. The main reason is that the solid electrolyte (ceramic) used in lithium metal batteries overcomes these defects in traditional lithium-ion batteries, and can easily break through the upper limit of energy density of traditional lithium-ion batteries before, which can exceed 400 Wh/kg, which is more than 30% higher than the current lithium-ion batteries. There is no doubt that if this technology can finally be applied to the automotive field, electric vehicles can have a longer range. However, many people still have concerns about lithium metal batteries, because in the organic electrolyte, lithium metal anode heterogeneous lithium deposition causes safety hazards, so metal lithium batteries have not been able to be applied, as for whether this breakthrough will have a role in commercialization, there is still a long way to go.
summary:
In 2021, the automotive industry has suffered a lot of blows, the recurrence of the epidemic, the chip crisis, the rise of raw materials, etc., a series of difficulties have followed. However, the new energy vehicle market is still developing rapidly, and technological innovation in power batteries has also been continuing, including the listing of the first domestic mass production car with a range of more than 1000km, and the official mass production of the world's first cobalt-free battery. More importantly, as one of the largest markets for the installed capacity of new energy vehicle power batteries, the future demand will be more exuberant, and this is bound to become a catalyst for the improvement of power battery technology, and it is easier to take the lead in the birth of some new technologies than foreign countries, so the new energy market in 2022 is also more worthy of our expectations.