There is no need to replace the battery when the vehicle is scrapped. Tesla successfully applied for 4,000 charge and discharge and 1.6 million km battery patents
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Recently, foreign media reported that Tesla CEO Elon Musk hopes to extend the service life of electric vehicle batteries to 1.6 million kilometers. New patents submitted by the company confirm that Tesla is accelerating toward this goal.
This new patent describes the nickel-cobalt-aluminum (NCA) electrode synthesis method and process used in the new lithium battery manufacturing process. The new process can greatly improve battery life and reduce battery manufacturing costs.
Tesla applied for US patents and international patents for this new technology. It is reported that Tesla has applied for international patents on this battery technology through the Canadian Tesla branch.
Tesla’s development of ultra-long-life batteries is no secret
The exposure of new Tesla battery patents has revealed from 2019 that Tesla is developing ultra-long-life batteries.
In 2019, Tesla ’s battery research partner Jeff Dahn published a new paper on batteries. The paper mentioned that the battery used in cooperation with Tesla has a mileage of more than 1.6 million kilometers. The new battery has a temperature of minus 40 degrees Celsius. Under extreme temperature, 4,000 charge and discharge cycles can be continued.
Also in 2019, Tesla frequently acted in the field of batteries, announcing the acquisition of Maxwell Battery Company, a self-built battery secret research center, and universities to collaborate on new battery technologies at a premium of 55% at US $ 218 million.
This time, the new patent filed by Tesla is called “Nickel Cobalt Aluminum (NCA) Electrode Synthesis Method”, which describes a new and efficient new electrode synthesis method in battery production, known as the nickel cobalt aluminum electrode heating process.
The previous heating method sometimes led to the formation of impurities called the lithium substrate (L15AIO4), and reducing the lithium content in the battery, although it can reduce pollution, but also leads to poor electrochemical performance.
In response to this phenomenon, the new patent mentions that the battery will be heated to a temperature sufficient to grow the single crystal. The corrected ratio of lithium to other metals will limit the formation of impurities during the first heating. Lithium will be heated a second time at a temperature below the first heating cycle.
Researchers participating in the patent pointed out that this process helps to develop single crystal NCA free of impurities, enabling the battery to reach more than 4,000 charge-discharge cycles, which in turn makes the battery life up to 1.6 million kilometers.
At this stage, the battery life of Tesla models is far less than 1.6 million kilometers. In fact, the vehicle design has already considered the 1.6 million kilometers use target. The current body structure, electric drive system and electronic system life can be done Yes, but the battery is undoubtedly a short board. The current life of Tesla’s power battery is only about 500,000 kilometers.
At that time, Tesla’s 1.6 million-kilometer battery will come out, which is definitely a revolutionary innovation for the automotive battery industry and a great achievement.
At present, the charge and discharge times of ternary lithium batteries on many models are about 1,000 times, and the most durable lithium iron phosphate batteries are only about 2,000 charge and discharge times; the number of new Tesla batteries that can reach more than 4,000 in the future After its introduction, there is no doubt that it has an overwhelming advantage.
However, this new battery is installed in all Tesla models, it does not mean that this car can be driven to 1.6 million kilometers, because the life of the car depends on many factors, and the quality of the car components, manufacturing and vehicle process are very large relationship.
It has been more than one hundred years since the birth of the internal combustion engine car, and it is not uncommon to have a mileage of more than 1 million kilometers in life.
The internal combustion engine technology is very mature, the production cost is relatively low, and the maintainability is very strong. Once the battery of the electric vehicle needs to be replaced, the cost is not only expensive but also very difficult to maintain. The development of long-life batteries is a problem that needs to be solved urgently, and the development of ultra-long-life batteries is also a big industry trend.
Two mainstream batteries for China’s new energy vehicles
At present, the two types of batteries used in China’s new energy vehicles are lithium iron phosphate batteries and ternary lithium batteries.
Lithium iron phosphate battery
This is a lithium ion battery using lithium iron phosphate as the positive electrode material (the positive electrode materials of lithium ion batteries mainly include lithium cobalt oxide, lithium manganate, lithium nickel oxide, ternary materials, and lithium iron phosphate, etc.).
- Advantages: low cost and cheap; safe and stable, high temperature resistant and non-flammable. Stability is currently the best among automotive batteries. As mentioned above, the number of charge and discharge times of about two thousand times is also the highest among the current battery types.
- Disadvantages: The energy density still has a large gap compared with ternary lithium batteries and lithium cobalt oxide batteries. Large and heavy, it will take up a lot of space in the car when loading, and force the weight of the whole car to increase. If the temperature is too low, it will seriously affect the service life.
Ternary lithium battery
This refers to a lithium battery whose cathode material is lithium nickel cobalt manganese ternary cathode material.
- Advantages: small size, high energy density, strong storage capacity (battery solution preferred for high-end electric vehicles), can better adapt to cold weather, charge and discharge at low temperatures, the battery is more stable.
- Disadvantages: low cycle life, a cost increase for vehicle use; higher cost (although after two years of upgrading the ternary lithium battery scale, the manufacturing cost has dropped significantly, and the low price model is still a high price); Poor stability, the ternary lithium battery has a high energy density ratio, and its safety and stability is necessarily lower than that of lithium iron phosphate lithium batteries (and the ternary lithium material has a particularly strong chemical reaction, which will decompose at 50 ~ 300 degrees Celsius. The electrolyte burns rapidly under the action of high temperature, and then deflagration occurs).
Graphene batteries have been heated up in recent years. In experiments, graphene batteries can reduce the charging time of several hours to less than one minute. The addition of graphene in the lithium battery can help the lithium battery reduce the heat during the production capacity, minimize the energy loss, avoid a large amount of energy from being wasted, reduce the damage of the heat to the battery, and increase the service life of the battery.
Graphene batteries, also known as “pure gold” batteries, add graphene to lithium batteries, the production cost is too expensive, about 2,000 yuan / gram, can not be used on a large scale, graphene batteries are currently only used for aviation aviation These industries, regardless of cost.
At present, graphene batteries of new energy vehicles are still in the experimental stage, and there is no mass production model yet.
Lithium iron phosphate batteries are currently widely used in the electric vehicle industry. In addition to small new energy vehicles, electric buses and other heavy vehicles are using lithium iron phosphate batteries.
The rapid development of ternary lithium batteries in China in recent years is inseparable from China’s new energy subsidy policies in the past few years. In recent years, China has tended to subsidize vehicles with long range and high battery system energy density. Move closer to the ternary lithium battery.
However, after the subsidy was reduced, many low-cost and high-cost models had to reconsider the use of lower-cost lithium iron phosphate batteries.
Why did Tesla develop ultra-long-life batteries?
Tesla currently uses a single 18650 battery and the latest 21700 battery. The life of these two types of batteries is far from the 1.6 million kilometers service life mentioned in Tesla’s new patent.
On January 4, 2017, Tesla announced the mass production of the new 21700 battery jointly developed with Panasonic.
After the 21700 battery is used, Tesla officials also claim that the energy density of the 21700 battery is increased by 20% compared to the 18650 battery. The system cost is expected to be reduced by about 9% and the weight is also reduced by about 10%. The current battery used by the Tesla Model 3 is Panasonic and LG Chemical are two companies that provide production. But whether it is an 18650 battery or a 21700 battery, it is a ternary lithium ion battery.
In 2017, among the 12 Tesla-operated fleets of “Easy-to-Use Vehicles” that were auctioned, the court estimated the residual storage value of the vehicles using the actual storage capacity of the battery.
These 12 Tesla Model S have an average driving range of 160,000 kilometers, an original endurance of 550 kilometers, and an average battery cycle of more than 290 times. After estimation, the average endurance is only 361 kilometers. The percentage of installation to calculate these vehicles decayed by 34.36% after 160,000 kilometers, which is equivalent to the battery is close to the end-of-life standard, which is far from its 5% officially announced by Tesla. This affected the consumer’s confidence in Tesla batteries to a certain extent at the time, and also seriously affected the preservation rate of later Tesla models in the secondary market.
The problem of battery attenuation has always plagued all new energy vehicle companies. Even the best Tesla in the industry is the same. After using ternary lithium batteries, Tesla can only maintain 70% of the electricity after 3,000 tests. Life expectancy is also extremely urgent.
1.6 million kilometers of ultra-long-life batteries are inseparable from the battery management system
After the advent of the 1.6 million-km battery described in Tesla’s new patent in the future, let’s not ignore another core. The battery is the core of the electric vehicle, and the core of the battery is the battery management system (BMS).
Many new energy vehicle companies, including Tesla, regard battery management systems as their core technology.
The battery management system is one of the most important systems for electric vehicles. It is related to the safety of the battery and is an important link used to connect the on-board power battery and the electric vehicle.
Its main functions include: battery status estimation, real-time monitoring of battery physical parameters, online safety alarms and warnings, charge and discharge control, thermal management, etc.
Among the “three major pieces” of Tesla’s electric vehicles, batteries, motors, and other components are purchased externally, but Tesla has always insisted on independent research and development of battery management systems.
Most of the core intellectual property rights applied for by Tesla are related to battery management systems, which shows the importance of battery management systems for new energy vehicles.
To understand simply, iPhone phones may not be as expensive as brand-name phones in various configurations, but through iOS system monitoring, each part cooperates with each other, so that the entire phone is in smoothness, power consumption and startup speed. The most ideal state.
Through predictions, after the advent of ultra-long-life batteries in the future, there may be a new battery management system launched, and the two will cooperate with each other to achieve the patented long life of 1.6 million kilometers. If there is no Tesla battery The management system assumes that the new battery is authorized to be used by other new energy vehicle companies and is also expected to reach a life of 1.6 million kilometers.
to sum up
At present, in the battery field, Tesla has initially cooperated with Panasonic to develop into three battery suppliers: Panasonic, LG Chemical and Ningde Times. The new patent reveals that Tesla wants to end the battery control of people and create an important three-electric system for electric vehicles, all of which are controlled by their own production.
In addition to being the industry leader in autonomous driving technology and battery management systems, I believe that in the field of self-developed new energy car batteries, Tesla’s new batteries will come faster than everyone expects. Tesla is a comprehensive technology company that builds cars and rockets. Musk’s ambitions are bigger than everyone thinks.
