The majority of netizens who watched for a while were confused: eating melons is too difficult now, right? The knowledge reserve cannot keep up with the speed at which Xiaomi lights up the technology tree.
What kind of technology,
In this issue, we will give you a comprehensive analysis of what kind of technology is the “silicon-oxygen anode battery” used in Xiaomi’s flagship model.
This technology has been applied in the power of electric vehicles, such as some time agoAmong the innovations in solid-state battery technology released by Weilai includes the use of silicon-carbon anode technology.
There are three main ways to increase battery capacity, namelyReplace the cathode material that can increase the energy storage density,Adopt brand newBattery separator technologywithReplace the negative electrode material that can increase the energy storage density.
the cathode material innovation for rechargeable batteries is mainly graphene cathode material. The function of this material is to increase the charging speed of the battery and cannot effectively increase the energy density;
The transformation of battery separator technology is mainly to make the battery separator thinner and thinner. However, the battery separator that is too thin can easily cause danger. Therefore, replacing the new negative electrode material is the most cost-effective way to increase the battery capacity.
This is mainly because traditional battery anode materials are carbon materials. Carbon materials as battery anodes are characterized by low expansion coefficient (about 10%) and low energy density (theoretical gram capacity 372mAh/g). Although they are ideal battery anode materials, Low battery energy density under the same volume;
The theoretical gram capacity of silicon material is about 4200mAh/g, but the expansion coefficient is high (about 300%); while the theoretical gram capacity of silicon oxide reaches 2615mAh/g, and the expansion coefficient is about 160%.
Silicon oxide anode,
Talking about human beings,Silicon oxide anode material has achieved a balance between battery energy density and expansion coefficient.
The use of silicon-oxygen anode batteries has obvious improvements to smart phones, which means that batteries of the same size will have a larger battery capacity, or the battery capacity can be controlled to make the mobile phone thinner and lighter.
Xiaomi 11 Pro/Xiaomi 11 Ultra choose the former, and the battery will reach 5000 mAh to ensure battery life.
Mass production of silicon-oxygen anode batteries is difficult
In the previous part, we compared the theoretical gram capacity and expansion coefficient of carbon,
silicon and silicon oxide as battery anode materials.
What can be found is that the expansion coefficient of carbon materials is the smallest, which is 10%;
Although the silicon anode material battery has a high energy density, this type of battery is easy to charge and bulge.
The safety ranking of the above three battery anode materials is carbon material>silicon material>silicon oxide material.
This requires breakthroughs in packaging materials, processing techniques, adhesives, etc., which will affect the final cost of the entire battery.
to sum up
Finally, we summarize the advantages and disadvantages of the silicon-oxygen anode battery. Advantages: large capacity per gram,
which allows the mobile phone to have a larger battery capacity within the same battery volume; disadvantages:
the negative electrode material has a large expansion coefficient, and charging safety needs to be controlled.
The application of electric vehicle technology such as silicon-oxygen anode battery to smart phones shows that Xiaomi is still thinking about it.
The silicon-oxygen anode battery has indeed improved the battery experience of smart phones.