Is it as good as it sounds? Exploring the secrets of the Aegis Dagger battery, how does it lead the way?

A few days ago, I returned to Hangzhou and listened to a technical presentation entitled "The Research and Development and Thinking of Geely's Aegis Dagger Battery" by Zhou Wei, a battery system integration design expert at Geely Automobile Research Institute, at Shanxia Art Museum in Xihu District. This is an activity that I have always been particularly interested in, so let me share some information that is worth paying attention to!

Regarding the Aegis Dagger battery, here are some numbers worth your attention:

-Cell length 580mm;

-Battery cell energy density 192wh/kg;

-Cycle life of 3,500 cycles, 40% higher than the industry average;

-1 million kilometers of health during the life cycle;

- The endurance retention rate at -10 degrees Celsius is 95.58% (-30 degrees is 90.54%);

-Average charging rate 2.45C;

-10%-80% charging in 17 minutes;

-11 layers of battery structure protection;

-6 layers of battery bottom protection;

-8 5mm steel needles will not catch fire when inserted together;

-Double explosion-proof valve exhaust (Figure 14), the exhaust path in the event of an accident is 50% shorter than that of a single explosion-proof valve;

The numbers may seem a bit blunt, so let me explain a few points I am concerned about:

(1) Security

The SHIELD Dagger battery uses a high-strength, high-heat-resistant diaphragm, a high-safety electrolyte, and self-developed "self-fusing technology". Once the battery cell is punctured, the aluminum foil will immediately melt and form an insulating layer to prevent short circuits and fires.

Here is a test experiment that needs to be told!

The Aegis Dagger battery was pierced by 8 steel needles at the same time. After being left for 1 hour, there was no smoke, no fire, and no explosion. In addition, the Aegis Dagger battery is the world's first battery to pass the 5.8mm real bullet penetration test. The diameter of the damage caused by the bullet is ≥60mm. Even in this case, the battery did not catch fire.

The Aegis Dagger battery has also passed the six serial tests of the China Automotive Technology and Research Center, which means that the same battery has been subjected to multiple tests in succession, including extreme working conditions such as immersion in sea waves, extreme cold in the plateau, high-frequency bottom scraping, 26-ton violent crushing, single-pack side column collision, and fire burning, without any safety issues.

Regarding safety, I specifically communicated a technical detail with Zhou Wei, which was also a discussion point I had repeatedly discussed when I was doing research and development at a car company - the distance between the battery cell and the side beam.

The size of the Aegis Dagger battery is 30mm, which is considered large on the market. I have seen 25mm and 20mm ones in the industry. Zhou Wei told me that there are even 15mm ones!

It looks like just a gap, but it actually represents a safety gap! In order to squeeze more batteries into the limited body size and extend the battery life, some car companies may make some compromises in this area!

The bottom line is firmly maintained, thumbs up!

(2) Cycle life

Still numbers: Geely Aegis Dagger battery life has been increased to 3,500 times.

In other words, it can withstand 3,500 charge and discharge cycles, and can provide a total range of more than 1 million kilometers. Ordinary private cars only run 20,000 to 30,000 kilometers a year, and it is estimated that it will be used for more than ten years without any problems.

In July this year, Geely displayed a Galaxy E5 ( parameters | inquiry ) endurance test car with a mileage of more than 300,000 kilometers. The Aegis Dagger battery on this car has undergone 921 charge and discharge cycles and has been used in extreme environments of high temperature, high cold and high humidity. Tests show that the battery still has a health level of 90.5%!

(3) Fast charging speed

At this point in time, the speed of recharging is the Achilles' heel of electric vehicles, and it is also one of the most important reasons why they cannot completely replace fuel vehicles.

The charging rate of Geely Aegis Short Blade battery is 2.45C, and SoC goes from 10-80% in just 17 minutes. Note that it starts from 10%!

If you are in a hurry, you only need to charge for more than ten minutes to add a lot of battery life. The 2.45C of the Aegis Dagger battery may seem ordinary, but it is much faster than the 30 minutes of many models of the same price.

(4) Low temperature performance

Low temperature is not friendly to electric vehicles, because low temperature will reduce the activity of chemical reactions inside the battery, which will reduce the battery life.

The solution of the Shield Dagger battery is:

Adding low-impedance film-forming additives to the electrolyte can significantly reduce the internal resistance during low-temperature discharge and improve low-temperature performance. Actual tests show that at 0°C, the Aegis Dagger battery can discharge 96.21% of its rated capacity, while the Long Blade battery can discharge 90.32%. At -10°C, -20°C and -30°C, the Aegis Dagger battery capacity retention rates are 95.58%, 93.56% and 90.54% respectively!

Anyone who has driven an electric car in winter should have an idea of ​​what this means!

I saw a promotional video on site, which was the latest workshop for producing Aegis Dagger batteries. It is called the fifth workshop in Geely in addition to the four traditional workshops of stamping, welding, painting and assembly. I talked to Mr. Zhou Wei, who revealed a few numbers to me:

- The automation rate of the battery cell itself is 100%;

-The automation rate of battery packs is about 90%;

I’m not sure what this ratio is in the industry, but it still surprised me. That 10% is mainly manual confirmation of some parameters and the installation of the battery pack wiring harness, etc.!

There is another piece of news worth pondering: SHIELD Dagger Battery welcomes any car brand to cooperate!