How can improvements in the packaging process of button batteries reduce their self-discharge rate?
Release Time : 2026-02-03
Button batteries, as miniature power sources, are widely used in smart wearables, IoT devices, and automotive electronics. Their self-discharge rate directly affects the device's battery life and reliability. In traditional packaging processes, insufficient internal sealing, high risk of electrolyte contact with external elements, and poor material compatibility are the core factors leading to accelerated self-discharge. In recent years, improvements in packaging processes, through multi-dimensional technological upgrades, have significantly reduced the self-discharge rate of button batteries, providing crucial support for improving battery performance.
Optimizing sealing performance is fundamental to reducing self-discharge. Traditional button batteries often use mechanical pressing or simple adhesive sealing processes. After long-term use, material aging or environmental stress can easily lead to seal failure, allowing external moisture, oxygen, and even dust to seep into the battery, causing electrolyte decomposition or electrode material corrosion, thus accelerating self-discharge. Improved processes introduce high-performance sealing materials, such as silicone or water-based acrylic sealants, which are evenly applied to the battery casing seams using automated dot-coating technology. After curing, a dense and flexible sealing layer is formed. This sealing layer not only effectively prevents external substances from intruding but also adapts to temperature changes and mechanical vibrations during battery use, preventing a surge in self-discharge due to seal failure. Reducing the risk of electrolyte leakage is another key focus of the process improvement. Electrolyte leakage inside a button battery directly leads to battery capacity decay and increased self-discharge rate. In traditional packaging processes, the connection between the battery casing and the top cover often relies on welding or riveting. However, welding defects or loose riveting can create tiny gaps, posing a risk of electrolyte leakage. The improved process uses laser sealing welding technology, which uses a high-energy-density laser beam to instantly melt the contact surface between the metal casing and the top cover, achieving contactless, high-precision fusion welding. This process not only eliminates problems such as incomplete welds and burn-through in traditional welding but also significantly improves the weld sealing performance, ensuring that the electrolyte is completely sealed inside the battery, thereby greatly reducing the risk of self-discharge caused by leakage.
Improved material compatibility is also crucial. If the positive and negative electrode materials, electrolyte, and packaging materials inside the button battery are chemically incompatible, it may trigger side reactions, leading to accelerated self-discharge. For example, additives in some traditional sealing materials may react with the electrolyte, generating conductive impurities that form internal microcircuits, exacerbating power loss. The improved process employs rigorous selection of encapsulation materials to ensure high compatibility with the battery's internal chemistry. For example, inert polymer materials are used as the sealing layer, or the metal casing undergoes special surface treatment to prevent reactions with the electrolyte, thereby reducing self-discharge caused by side reactions.
The refined design of the encapsulation structure further enhances self-discharge control. Traditional button battery encapsulation structures are often based on simple casings with low internal space utilization and limited contact area between electrode materials and electrolyte, potentially leading to uneven local reactions and self-discharge. The improved process optimizes the battery's internal structure design, such as using multi-layer composite electrodes or three-dimensional electrode structures, increasing the contact area between electrodes and electrolyte, promoting uniform charge transfer, and reducing self-discharge caused by local reaction differences. Simultaneously, the improved encapsulation structure also enhances the battery's mechanical strength, reducing internal structural deformation caused by external pressure or vibration, further lowering the risk of self-discharge.
Furthermore, automated and standardized production of the encapsulation process is also crucial for reducing self-discharge. Traditional manual or semi-automatic encapsulation processes are prone to inconsistent battery performance due to operational variations, and some batteries may have higher self-discharge rates due to encapsulation defects. The improved process, introduced into a fully automated production line, uses precision equipment to control packaging parameters such as sealant application amount and laser welding energy and time, ensuring highly consistent packaging quality for each battery. This standardized production not only reduces self-discharge variations caused by process fluctuations but also improves production efficiency and lowers manufacturing costs.
The improvements to the button battery packaging process, through multi-dimensional technological upgrades including optimized sealing performance, reduced electrolyte leakage risk, improved material compatibility, refined structural design, and automated production, significantly reduce the battery's self-discharge rate. These improvements not only extend the button battery's lifespan and improve device endurance but also provide a solid guarantee for the reliable operation of smart electronic products. With continuous innovation in packaging technology, the self-discharge control of button batteries will be further optimized, driving their widespread adoption in more high-end application areas.