Battery packaging analysis

The basic structure of the battery The basic structure of the battery consists of three parts: the battery core, the protective plate, and the shell. 1. Battery: The battery is the most important part of the battery and the carrier of energy conversion. Our company currently processes polymer lithium ion batteries and cylindrical lithium ion batteries. The basic parameters of the battery are: capacity, internal resistance, cycle life, etc. 2. Protection board: The protection board is an electronic functional module that protects the normal operation of the battery cell and prevents abnormal accidents. The main components are IC and MOS tube. The IC is a component that monitors the voltage of the cell, and the MOS tube is a switch. In the entire module, the IC controls the switching state of the MOS tube by testing the current of the working circuit and the voltage across the cell, thereby controlling the charging and discharging circuit to prevent the battery from overcharging, overdischarging or overcurrent. The important parameters of the protection board are: overcharge protection voltage, overcharge protection recovery voltage, overdischarge protection voltage, overdischarge protection recovery voltage, short circuit protection current, self-consumption current, PCM internal resistance, etc. The above parameters can be measured by special equipment or analog circuits. 3. Shell: The shell is the shell that fixes the battery core and the protection board together, seals and completes the matching function with the host. The outer shell is often divided into a bottom shell and a face shell. Generally, after mating with the host, the one that leaks outside is the face shell, and the other is the bottom shell. Commonly used materials for the shell are: ABS, ABS+PC, PC, etc. The important indicators for weighing the shell are: color, material, fit, mechanical strength, etc. The key process of battery packaging 1. Tin soldering: Tin soldering is a process that uses solder wire to connect conductors together and achieve a good conduction effect. The factors that affect the quality of solder include soldering temperature, main body material, solder material and so on. The welding temperature in battery packaging is generally required to be controlled at 360±10°C. Materials that are easy to solder include gold, silver, copper, tin, nickel, steel, etc. The defects that are easy to appear in soldering are: false soldering, false soldering, over soldering, etc. 2. Plastic shell packaging (also known as ultrasonic welding and crimping): The packaging of commonly used plastic shells uses ultrasonic welding. The principle is to use ultrasonic waves to transfer energy to two contact surfaces. High-frequency vibration of the contact part generates heat and melts the contact surface And bonding. The important parameters that affect ultrasonic welding are: equipment power, equipment energy, pressure, welding time, etc. Three, detection 1. Cell detection: conventional items include: capacity, cycle life, internal resistance, voltage, self-discharge, etc. Other items include: high temperature discharge performance, low temperature discharge performance, short circuit, nail piercing, etc. 2. Protection board: electrical performance detection parameters include: overcharge protection voltage, overcharge protection recovery voltage, overdischarge protection voltage, overdischarge protection recovery voltage, short circuit protection current, self-consumption, PCM internal resistance, etc. Shape and structure: The leaking part of the gold finger has no deviation, sinking, bright color and no spots, and the thickness of the gold layer is 0.3μm. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: Brief description of lithium battery charging pile