Explain the structure principle of lithium battery in detail

The structure principle of lithium battery If you have seen lithium battery cells, you must know that its appearance is similar to our commonly used No. 5 battery, but the size is slightly larger. We can see the positive and negative electrodes of the battery from the outside, as well as the entire battery casing. And what is the internal structure and working principle of the battery? The inside of the battery is mainly composed of positive electrode, negative electrode, electrolyte and separator. These materials are encapsulated in a cylindrical steel bottle. Because there are many tiny holes in the cathode material, it can store a lot of electrons. In the discharge process, these electrons move to the positive electrode material through the external circuit. When the battery is connected to an external electrical appliance, it will form a loop from the positive electrode to the electrical appliance and then to the negative electrode. This is the basic working principle of the battery. The anode material is actually graphite, which is very common to us. Since graphite naturally has many holes and good conductivity, its capacity to capture electrons is much greater than that of positive electrode materials. Therefore, for lithium batteries, the critical bottleneck is stuck in the positive electrode material. This is also the reason why major battery companies continue to improve the performance of cathode materials in order to increase the charge (energy density) of lithium batteries. The ternary lithium and lithium iron phosphate we often refer to are all cathode materials. In the field of traditional lead-acid batteries, the electrolyte uses extremely low-cost dilute sulfuric acid. This is why we sometimes need to fill a new battery with liquid once when replacing the car battery when it is used for the first time. This liquid is the electrolyte. Since the important component of dilute sulfuric acid is water, water will appear conductive under the use of acidic particles, so it can form a current loop inside the battery. However, due to the poor conductivity of water, the voltage of traditional lead-acid batteries is only less than 2 volts, and the voltage of a single cell of the lithium battery we use can reach 3-4 volts, so lithium salt should be used instead of traditional water-based electrolysis. liquid. The purpose of the diaphragm is to block electrons and allow electrons to flow along the path of the external circuit, but ions can pass through the diaphragm, so that it can form a loop without short-circuiting the positive and negative electrodes. The principle of charging and discharging of lithium batteries The essence of the reason why lithium batteries can be charged and discharged is the process of converting electrical energy into chemical energy when charging, and converting chemical energy into electrical energy when discharging. Simply put, when charging, lithium ions are inserted from the positive electrode material into the negative electrode material through the electrolyte; when discharging, lithium ions are inserted into the positive electrode material from the negative electrode material through the electrolyte, and electrons pass through the external circuit to form a current. Regarding lithium batteries, the performance of the positive electrode material is of utmost importance. It must have good electrical conductivity, good compatibility with the electrolyte, and excellent stability. Disclaimer: Some pictures and content of the articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: What are the uses of lithium battery positive and negative materials