Ratio of negative electrode of energy storage battery

What is the ratio of positive and negative electrodes in lithium batteries?

The ratio of positive and negative electrodes in graphite negative electrode lithium batteries can be calculated based on the empirical formula N/P = 1.08, where N and P are the mass specific capacities of the active materials of the negative electrode and positive electrode respectively. The calculation formulas are as follows (1) and (2).

How does negative electrode capacity affect battery capacity?

When the negative electrode capacity is high, that is, when the N/P ratio increases, the battery capacity increases accordingly; when N/P is greater than 1.0, the cathode capacity is insufficient relative to the negative electrode capacity, and the battery capacity is limited by the positive electrode capacity.

What is n/p ratio in lithium ion batteries?

The capacity ratio between the negative and positive electrodes (N/P ratio) is a simple but important factor in designing high-performance and safe lithium-ion batteries. However, existing research on N/P ratios focuses mainly on the experimental phenomena of various N/P ratios.

What is the negative electrode potential of a battery?

The negative electrode potential of the battery with an N/P ratio of 0.87 dropped from 1.56 V to 1.50 V, while the negative electrode potential of the battery with an N/P ratio of 1.00 remained basically unchanged, only decreasing from 1.56 V to 1.54 V.

What is the ratio of specific capacity of positive and negative electrode?

The ratio of specific capacity of positive and negative electrode is the inverse ratio of respective active masses. For safety and lifetime reasons, the practically required capacity of negative electrode needs to be increased, thus leading to an increase of negative electrode‘s mass and finally to (N:P)m active mass ratio.

What is a good charge capacity for a positive electrode?

For example, when the first-round efficiency of the positive electrode is 80%, the above-mentioned positive charging capacity is 181 mAh/g, then P = 32.58 mAh/cm2, N/P = 0.96. At this time, the surface density of the positive and negative electrodes should be adjusted so that N/P is greater than 1, preferably around 1.03.