Writing an article? /? Julie
Editor? /? Zhang Nan
Design? /? Du? triumphant
Source? /? Eric, by Fred? Lambert
Tesla has applied for a patent for a new technology, which will provide electrolyte solution for a new metal lithium battery or anodeless battery.
In the past year, Tesla's battery research partner Jeff Dagen (Jeff? Dahn) and he is at Dalhousie University (Dalhousie? University) has been working for Tesla to improve energy density and battery life, while reducing costs.
Last year, they announced the test results of a new type of battery, which is a lithium-ion battery with the next generation of "single crystal" NMC cathode and a new advanced electrolyte. Dagen's team conducted extensive tests on these batteries. According to the test results, they believe that this battery can drive electric vehicles for more than 6.5438+0.6 million miles (6.5438+0.6 million kilometers) and be used for energy storage in the power grid for at least 20 years, which is two to three times longer than Tesla's existing batteries.
They tested the battery under different conditions and cycles. Even at the extreme temperature of 40 degrees Celsius, these batteries can last 4,000 cycles. With the help of the active cooling system, just like Tesla's battery pack, it can increase the cycle times of the battery to more than 6,000 times, which means that a good battery pack can easily travel 1 10,000 miles. Controlling the charging state below 100% is also helpful to prolong the service life. They believe that this battery will be used in "robot taxis" (robo? Taxi) is particularly useful.
As pioneers of lithium-ion battery technology, Dagen and his team have been studying the next generation battery technology in addition to improving the existing technology.
Last year, the team applied for a patent for Tesla's anode-free lithium metal battery, which they thought might be the next big event to replace solid-state batteries in battery technology. The team's paper basically explains how they solved the problem of replacing the traditional graphite anode with lithium metal without using solid electrolyte. If successful, it will realize the commercialization of batteries with higher energy density and longer duration in a shorter time than solid-state batteries.
Now, the Dagen team has applied for a new patent for Tesla Canada Research Group, which proves that they are still studying new batteries: "Electrolyte containing lithium difluoro (oxalic acid) borate and lithium tetrafluoroborate is used for lithium metal and anode-free batteries".
Tesla wrote in the patent application:
"Rechargeable batteries are an indispensable part of electric vehicle energy storage system and power grid energy storage (such as standby power supply in case of power failure, as part of microgrid, etc.). Some such rechargeable battery systems include lithium metal and anode-less lithium batteries. Compared with traditional lithium-ion batteries, metallic lithium and anode-free lithium batteries have certain advantages because of their higher energy density. Anode-free batteries are also cheaper and easier to assemble because there is no anode coating. However, the challenges faced by lithium metal and anode-free lithium batteries hinder their wide adoption. Improving some characteristics of lithium metal and anode-free battery system will make this system more widely used. For example, it is very important to develop an electrolyte composition that can achieve commercially acceptable lithium metal cycle performance and anode-free lithium batteries. Prior to this, it was generally recognized in the industry that the electrolyte containing only lithium difluoro (oxalic acid) borate ("LiDFOB") salt can best improve the capacity retention capacity of lithium metal and anode-free lithium batteries. "
In a word, this kind of battery has great advantages in energy density and cost, but its life needs to be improved.
Dagen's team said that their new electrolyte will help improve this situation:
The provided electrolyte contains lithium difluoro (oxalic acid) borate and lithium tetrafluoroborate, as well as solvent components for lithium metal or anode-less rechargeable batteries, and a method for improving battery capacity by using the electrolyte. The invention also provides a rechargeable battery system, which comprises a lithium metal or anodeless battery, and electrolyte solution and solvent components, including lithium difluoro (oxalic acid) borate and lithium tetrafluoroborate. The system described in this paper has higher capacity retention capacity.
In the patent application, they did publish the test results, showing that the capacity retention capacity of the battery has improved, but at present, it seems that the battery life cycle has not increased to more than 50 times. They need to cycle the battery more to commercialize it.
Earlier this year, Tesla researchers published a research result, describing a new type of battery, which takes advantage of the life of lithium-ion battery and the high energy density of lithium-metal battery, and uses the hybrid lithium-metal battery as a battery life tool for all-electric vehicles.
"Improving the energy density of batteries will reduce the cost of electric vehicles and extend the mileage. Replacing graphite negative electrode in traditional lithium ion battery with metallic lithium can significantly improve energy density. However, lithium metal anode has the problems of fast capacity loss and short battery life. In order to develop a long life and high energy density battery, we propose a lithium ion/metallic lithium hybrid battery, which is realized by purposefully plating metallic lithium on graphite. Although excessive lithium electroplating is usually a degradation mechanism in traditional lithium ion batteries, we have achieved reversible graphite lithium electroplating in optimized double salt electrolyte. In addition, since batteries usually don't recover to 100% capacity, these hybrid batteries can operate in lithium-ion mode with little degradation, and their capacity is increased through periodic fully charged lithium metal cycles during most of their life. "
However, it should be noted that Tesla, like most other companies, sometimes applies for patents for technologies that will not be put into production.
More information about Tesla's battery plan will be announced during the "Battery Day" on September 15.
This article comes from car home, the author of the car manufacturer, and does not represent car home's position.