February 26, 2019

Why is the larger volume, the larger the battery capacity, the smaller the internal resistance?

In general, the capacity of a battery is proportional to the square root of the plate area and thickness.
The paste-type plate was tested in a density of 1.300 g/cm3 electrolyte to obtain an empirical formula for calculating the capacity of the plate:
Monolithic plate capacity = 0.145 × plate width × plate height × plate square thickness
Single cell capacity = number of single positive plate × single plate capacity
The larger the capacity, the larger the area, and the smaller the resistance of the current.
The internal resistance of the lithium battery must be as small as possible. The smaller the internal resistance, the less energy is wasted for the battery and the heat generation and rate of the battery are helpful.
The internal resistance of the battery is related to the capacity and type of the battery.
Generally speaking, the larger the capacity, the smaller the internal resistance of the battery.
The internal resistance of the battery rate type under the same capacity is smaller than that of the capacity type.
For example, the most common 18650 battery internal resistance ranges from a dozen to several tens of milliohms.
In addition, the same capacity and type of battery can also reduce the internal resistance by technical process, mainly depending on whether the input cost is feasible.