Principle And Composition Of Storage Battery

Principle And Composition Of Storage Battery

Date:Apr 07, 2021

Principles of Chemistry

The equation is as follows:

Total reaction: Pb (s) + PbO2 (s) + 2h2so4 (AQ) invertible symbol 2pbso4 (s) + 2H2O (L)

During discharge: negative Pb (s) - 2E - + SO42 - (AQ) = PbSO4 (s)

                            positive  PbO2 (s) + 2E - + SO42 - (AQ) + 4H + (AQ) = PbSO4 (s) + 2H2O (L)

                            Total      Pb (s) + PbO2 (s) + 2h2so4 (AQ) = 2pbso4 (s) + 2H2O (L)

Electrolytic cell during charging

Cathode PbSO4 (s) + 2E - = Pb (s) + SO42 - (AQ)

Anode PbSO4 (s) + 2H2O (L) - 2E - = PbO2 (s) + SO42 - (AQ) + 4H + (a)

Note: (the cathode during charging is the negative during discharging)

Physical composition

The main components of lead-acid batteries are as follows:

Anode plate (PbO2) -- > active material

Cathode plate (spongy lead. Pb) -- > active material

Electrolyte (dilute sulfuric acid) -- > sulfuric acid (H2SO4) + distilled water (H2O)

Battery shell, cover (PP ABS flame retardant)

Isolation panel (AGM)

Safety valve

Positive and negative pole, positive and negative pole, etc

Physical quantity connection

Relationship between electric quantity and voltage

The remaining capacity of the battery can be roughly obtained by measuring the voltage of the battery. The relationship between the voltage and the remaining capacity of 12V lead acid battery for vehicles is shown in the table below:

Voltage (V)Remaining capacity
12.1 50%
11.8 30%
11.6 20%


Relationship between internal resistance and capacity

The relationship between internal resistance and capacity of battery has two meanings:

The relationship between internal resistance and rated capacity, and the relationship between internal resistance and SOC of the same type of battery. More than ten years ago, people tried to use the change of internal resistance (or conductance) of VRLA battery to detect the capacity of battery on line and predict the battery life, but they failed to do so. People put forward higher and higher requirements for the high current discharge capacity of power battery, which requires reducing the internal resistance of battery as much as possible. Therefore, this paper will further explore and clarify the internal relationship between internal resistance and capacity of some commonly used batteries.

Valve controlled seal

At present, valve regulated lead-acid battery has gradually replaced open flow electrolyte lead-acid battery, which is widely used in post and telecommunication power supply, UPS, energy storage power supply system, etc. The power VRLA battery has been widely used in electric bicycle. These areas require on-line detection of the state of charge of the battery.

Relationship between internal resistance and state of charge of battery

SOC of battery refers to the ratio of the capacity that the battery can discharge to its rated capacity. This data is very important for the power supply system of post and telecommunication and the power battery pack in use.

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