What is a high discharge rate battery?

What is a high discharge rate battery?

A high discharge rate battery generally refers to a lithium-ion battery with a continuous discharge capacity of ≥ 3C. A lithium-ion battery is a rechargeable high rate battery that relies heavily on the movement of lithium ions between the positive and negative electrodes to work. In the process of charging and discharging, Li+ is embedded and de-embedded back and forth between the two electrodes: when charging the battery, Li+ is de-embedded from the positive electrode and embedded in the negative electrode via the electrolyte, and the negative electrode is in a lithium-rich state; the opposite is true when discharging. This is a battery that generally uses materials containing lithium as electrodes. It is the representative of modern high performance battery.

The characteristic of high discharge rate battery is to be able to discharge at a large rate, and the mainstream of its positive and negative electrode system is still lithium cobaltate and graphite system, of course, the particle size of active materials are much smaller than the conventional high capacity system. Generally, the particle size of lithium cobaltate D50 is 5-6um, and the particle size of graphite is 7-8um, the smaller the particle size, the larger the BET and the higher the reaction activity. The electrolyte system is adopted with low viscosity and high lithium salt concentration, and its conductivity is high. As for the isolation membrane, it is important to have high porosity and high permeability.

In terms of auxiliary materials, in order to meet the high rate discharge characteristics of high rate batteries, it is inevitable to add more conductive agents to enhance the electronic conductivity of the pole piece, usually, the conductive agents are a mixture of a variety of conductive agents.

In general, in the material system, in order to achieve the multiplier discharge, in the electronic conductivity and ionic conductivity should be improved, once both are improved, then it means that the entire chemical system of the high rate battery is more active, the reaction speed of chemical reactions to be faster, from another aspect, is once the internal, thermal runaway is more likely to occur.

Performance of high rate battery
① Continuous discharge capacity; ② Instantaneous discharge capacity; ③ Charging capacity; ④ Cyclic discharge capacity; ⑤ High and low temperature discharge capacity; ⑥ Safety performance.


Leave a comment

All blog comments are checked prior to publishing