How does a car battery work? (Starting battery i.e. storage battery)
The car starting battery is under the hood, the shape is usually a rectangular box, it is the car battery, is the core component of the car electrical system, there is a battery vehicle can start normally, when we start the vehicle, the battery will first supply power to the starter motor, the starter motor will engage the pinion to the engine’s flywheel, and then rotate the gears to drive the engine’s crankshaft, thus starting the engine. The starter motor needs to provide a huge amount of energy to get the flywheel to turn, so it uses a lot of power, which the battery needs to provide. When the engine is able to run on its own, the pinion gear will disengage from the engine’s flywheel.
Types of car batteries
The main types of car starting batteries are lithium-ion, lead-acid, and nickel-metal hydride batteries. This article mainly introduces the working principle of lead-acid batteries and lithium-ion batteries and related contents.
1.Lead-acid battery
1.1 There are generally 6 cells inside the battery, each cell contains a battery, each cell produces a voltage of about 2.1 volts, these cells are connected in series, the negative terminal of one battery to the positive terminal of another, so that the 6 cells can provide a voltage of about 12 volts or so.
Each cell of the battery contains positive plates, negative plates, electrolyte, shell, positive and negative plates are made of lead oxide and pure lead materials respectively, and the electrolyte is a mixture of sulfuric acid and water, which are lead-acid batteries.
1.2 Batteries arranged neatly immersed in sulfuric acid, sulfuric acid will cause a chemical reaction between the lead dioxide and lead plates, the battery in the discharge process, the negative plate and the electrolyte will undergo a chemical reaction, releasing a large number of electrons, and through the wires to flow to the positive electrode, and then connected to the wires of the electrical equipment can work normally, but will not last for a very long time, when the reaction of the chemicals needed to be depleted (i.e., insufficient battery power) sulfuric acid will be diluted. ) the sulfuric acid will be diluted and at the same time the lead sulfate from the reaction will build up on the two electrodes, resulting in the electrodes of the two materials becoming more and more similar, and eventually equilibrium will be reached (the battery will not be able to supply power).
1.3 Battery chemistry can be reversed, in the engine compartment, there is an engine driven generator, when the generator is working and running, it generates electricity and feeds it back into the battery, the direction of the current is opposite to the discharge of the battery, thus charging the battery.
2. Lithium-ion batteries (lithium iron phosphate batteries)
Lithium iron phosphate is used for the positive electrode. The advantages of iron phosphate lithium ion batteries are that it is difficult to damage the internal heat structure, high safety, and lower manufacturing costs than manganese batteries because iron is used as the raw material. However, the voltage is lower than other lithium-ion batteries.
The working principle of lithium-ion batteries: the battery has a positive electrode and a negative electrode made of metal material, and relies on lithium ions to move back and forth between the positive and negative electrodes to work. During charging and discharging, lithium ions are embedded and de-embedded back and forth between the two electrodes. When charging, lithium ions from the positive electrode embedded, through the electrolyte embedded in the negative electrode, the negative electrode is in a lithium-rich state; discharge is the opposite, lithium ions from the negative electrode embedded, through the electrolyte embedded in the positive electrode, the positive electrode is in a lithium-rich state. In this way, through the movement of lithium ions, the battery is able to store and release energy.
Advantages of lithium-ion batteries (lithium iron phosphate):
1 Longer battery life, more than twice that of lead-acid batteries
2 higher safety performance, lithium iron phosphate battery cell electric coupling welding, more safe and reliable
3 can be stored for a long time, fully charged batteries can be stored for more than a year, can still be used normally
4 environmentally friendly, no corrosive liquids, no harmful heavy metals, can protect the environment
5 very convenient to use, can be installed in any direction, daily life without maintenance.
