Do you know the design concept of 18650 cylindrical battery? Now let me introduce for you.
First, If the injection volume is insufficient, it will result in incomplete internal infiltration, large internal resistance, fewer cycles, etc. Serious will lead to lithium evolution and further danger; If the injection volume is too large, it will result in insufficient internal space (large internal pressure), rapid capacity attenuation, increased cost, etc. Here, the rapid capacity attenuation caused by liquid injection is due to the reaction of the rich free electrolyte with the lithium-carbon compound of the negative electrode with greater activity and the consumption of effective substances, especially at high temperature and during the charging process.
Second, the tightness of 18650 rechargeable cylindrical battery is calculated by dividing the sum of the bottom areas of the positive electrode, the negative electrode, the diaphragm and the coil gap by the inner bottom area of the cylindrical battery. Generally 88%-93%. Similarly, the specific tightness depends on the purpose of the battery and the various performances of the final battery you require. If the tightness is too low, it will lead to space waste, increased cost, difficult infiltration of electrolyte (liquid consumption), cell shaking, etc. Excessive tightness will lead to insufficient space caused by subsequent cell expansion, which will affect electrochemical performance and easy disconnection of CID with large internal pressure.
Third, the increase of the number of poles can only increase the AC internal resistance of the battery in a limited way, which is not directly related to the DC internal resistance in the final use process. Moreover, increasing the number of lugs will increase the difficulty of battery process design, increase the cost and end-use risk. Therefore, in order to increase the final battery capacity or multiplying power performance, whether it is feasible to increase the number of lugs unilaterally must be carefully designed.