Date: 2024-07-11 hits: 211
Soft pack batteries have attracted widespread attention due to their lightweight, flexible, and high energy density characteristics. The hydrogenation problem of soft pack batteries has become a key factor restricting their performance and safety. Below, we will delve into the reasons for the oxidation of the polar ears in soft pack batteries and explore various solutions, including surface treatment, electroplating process, metal strip treatment, testing and monitoring, heat dissipation strategy, material selection, regular inspection and maintenance, and design optimization.
A. The reasons for the oxidation problem of the polar ears in soft pack batteries
The problem of ear oxidation in soft pack lithium-ion batteries is usually closely related to the ear material and its surface treatment process. As an important component of a battery, the pole ear is responsible for leading out or introducing current into the battery. When the polar ear material undergoes oxidation, it may lead to a series of problems, affecting the performance and safety of the battery.
Copper plated nickel ear is a common type of ear material, in which the main function of the nickel layer is to prevent copper oxidation. However, if the adhesion of the nickel layer is insufficient, under long-term high current or driving vibration, the coating may have insufficient performance, which can cause micro short circuits or self discharge inside the battery cell, as well as problems such as increased contact resistance or detachment of welding points outside the battery cell.
B. The method to solve the problem of oxidation of the pole ear of soft pack battery
1. Surface treatment: In order to ensure the oxidation resistance of the pole ear, surface treatment is a crucial step.
For nickel-plated copper electrodes, secondary treatment of the passivation film on the surface can improve the solderability and electrohydraulic corrosion resistance. This can effectively reduce the occurrence of electrode oxidation and extend the service life of the battery.
2. Plating process: The choice of plating process is crucial for the uniformity and adhesion of the nickel layer.
Nickel plating and electroless nickel plating are common methods, where the thickness of the electroless nickel plating layer should be controlled at 1.8±0.3um, and the thickness of the electroless nickel plating layer should be in the range of 1.0±0.3um. This can ensure the quality of the nickel layer and improve the antioxidant capacity of the pole ear.
3. Metal belt treatment: for the thickness of more than 0.2mm of the power pole ear metal belt, side cutting treatment is necessary.
This avoids the risk of reduced insulation impedance and gas leakage, while improving the reliability of the pole ear.
4. Testing and monitoring: The penetration test and heat seal strength test after the electrolyte immersion are the key steps to ensure the bond strength of the pole glue and the metal conductor. For example, a Japanese EV cell manufacturer has strict technical requirements for EV and ESS poles, and these tests can ensure the quality and safety of the battery.
5. Heat dissipation strategy: overheating is an important factor leading to the acceleration of electrode oxidation.
Therefore, research and implementation of effective heat dissipation strategies can reduce the risk of electrode oxidation. This includes optimizing the structural design of the battery, using heat dissipation materials, and so on.
6. Material selection: Choose a material with better antioxidant properties, or develop a new type of pole material, can fundamentally improve the corrosion resistance and stability of the pole ear. This is of great significance for improving battery performance and safety.
7. Regular inspection and maintenance: Regular inspection and maintenance of the battery is the key to timely detection and solution of the polar oxidation problem. Through regular inspection, the oxidation phenomenon of the pole ear can be found in time, and corresponding maintenance measures can be taken to ensure the normal operation of the battery.
8. Design optimization: By optimizing the design of the battery to reduce the force and vibration of the pole ear, the risk of oxidation caused by mechanical damage can be reduced. Reasonable design can improve the overall reliability and stability of the battery.
C. Summary
The problem of anode oxidation of soft pack batteries is one of the key factors affecting battery performance and safety. Through the comprehensive application of surface treatment, plating process optimization, metal strip treatment, test monitoring, heat dissipation strategy, material selection, regular inspection and maintenance and design optimization, the problem of electrode oxidation can be effectively solved or slowed down, and the performance and service life of the battery can be improved.
