12V200Ah LiFePO4 Battery

12V200Ah LiFePO4 Battery

The characteristics

● Cycle life is super long; 100%DOD could reach 2000 times; 80%DOD could reach 6000 Times

●  Excellent Safety performance.

●  Good deep discharge performance

In order to achieve better development of lithium-ion batteries, it is necessary to figure out which factors are  limiting the rate performance of the battery.

Improve the lithium ion diffusion capacity of positive and negative electrodes

The rate of deintercalation and embedding of lithium ions inside the positive/negative active material, that is,  the speed at which lithium ions run out of the positive/negative active material, or from the positive/negative surface to the inside of the active material to find a position to “settle” How fast is the speed, which is  an important factor affecting the charge and discharge rate.

For example, there are many marathons in the world every year. Although everyone starts at the same time, the  road width is limited, but there are many people involved (sometimes as many as tens of thousands), causing mutual crowding and the body of the participants. The quality is uneven, and the team will eventually become an extra  long battle. Someone soon reached the end, some people were late for a few hours, some people ran to fainting, and they stopped eating halfway.

The diffusion and movement of lithium ions in the positive/negative poles is basically the same as that of the  marathon. They run slower and run faster, and the length of the roads they choose varies, which seriously restricts the end of the game (everyone is Run it). So, we don't want to run a marathon. It's better that everyone runs  100 meters. The distance is short enough. Everyone can reach the end quickly. In addition, the runway should be wide enough, don't crowd each other, and the roads should not be twisted and twisted. The straight line is The  best is to reduce the difficulty of the game. As a result, the referee made a sound, and the thousands of horses and horses rushed to the end. The game ended quickly and the rate performance was excellent.

At the positive electrode material, we want the pole piece to be thin enough, that is, the thickness of the active  material is small, which is equivalent to shortening the running distance, so it is desirable to increase the compaction density of the positive electrode material as much as possible. Inside the active material, there should  be enough hole clearance to leave the passage for the lithium ions. At the same time, the distribution of these "runway" should be uniform. There should be some places, and some places are not. This is to optimize  the structure of the positive electrode material. Change the distance and structure between the particles to achieve a uniform distribution. The above two points are actually contradictory, increasing the compaction density.  Although the thickness is thinner, the particle gap will become smaller, and the runway will appear crowded. Conversely, maintaining a certain particle gap is not conducive to making the material thin. So you need to find  a balance point to achieve the best lithium ion migration rate.

In addition, the positive electrode materials of different materials have a significant influence on the diffusion  coefficient of lithium ions. Therefore, selecting a positive electrode material with a relatively high lithium ion diffusion coefficient is also an important direction for improving the rate performance.

The treatment idea of the anode material is similar to that of the cathode material, and it mainly starts  from the structure, size and thickness of the material, reduces the concentration difference of lithium ions in the anode material, and improves the diffusion ability of lithium ions in the anode material. Taking carbon-based  anode materials as an example, in recent years, research on nano-carbon materials (nanotubes, nanowires, nanospheres, etc.), instead of the traditional anode layer structure, can significantly improve the specific surface  area, internal structure and structure of the anode material. Diffusion channels, which greatly improve the rate performance of the anode material.