How can the stamped metal contact piece in a battery connector avoid excessive temperature rise and performance degradation under high current?
Publish Time: 2025-12-31
In new energy vehicles, energy storage systems, power tools, and high-end consumer electronics, battery connectors serve as crucial interfaces for power transmission. Their internal stamped metal contact pieces must withstand high currents of tens or even hundreds of amperes over extended periods. Inappropriate design or materials can lead to excessively high contact resistance, causing significant Joule heating, resulting in localized temperature rise, material softening, accelerated oxidation, and ultimately, contact failure, signal interruption, and even fire risks. Effectively suppressing temperature rise while ensuring miniaturization and high reliability has become the core challenge in the development of battery connector metal contact pieces.1. Optimizing Highly Conductive and Highly Elastic Alloy MaterialsThe contact material is the first line of defense for temperature control. Commonly used stamping materials such as phosphor bronze, beryllium copper, and high-strength copper alloys achieve a balance between conductivity and elastic modulus. Beryllium copper combines ultra-high strength with good conductivity, making it suitable for high insertion/extraction forces and high current applications. Meanwhile, novel dispersion-reinforced copper enhances heat resistance and stress relaxation resistance through nano-precipitated phases, maintaining over 80% of its initial positive force even at 150℃, effectively preventing contact pressure drop due to material creep.2. Optimizing Contact Structure to Reduce Contact ResistanceContact resistance consists of shrinkage resistance and film resistance. To reduce the former, contacts are often designed with multi-point elastic contact structures to increase the actual conductive area; simultaneously, ensuring the flatness and surface roughness of the contact surface avoids current concentration at microscopic bumps. To suppress the latter, key contact areas are treated with gold or silver plating to form a low-resistance, oxidation-resistant conductive film. The gold layer is not only chemically inert but also maintains a stable conductive path under fretting wear, significantly delaying temperature accumulation.3. Enhancing Heat Dissipation Paths and Thermal Management DesignHeat must be dissipated promptly to prevent localized accumulation. The contact body conducts heat to the connector housing or PCB copper foil through a high thermal conductivity copper alloy substrate. Some high-power connectors also integrate heat dissipation fins on the back of the terminals or fit tightly against the metal bracket, utilizing both convection and conduction mechanisms to accelerate heat dissipation. Furthermore, a reasonable layout of terminal spacing, avoiding dense arrangement, can reduce thermal coupling effects and prevent the accumulation of "hot spots."4. Precise Control of Stamping Process Ensures ConsistencyIf burrs, warping, or springback during the stamping process are not strictly controlled, it will lead to uneven contact force and excessively high current density at local contact points. Advanced manufacturing employs high-precision progressive dies, deburring and stimulating light treatment, and online visual inspection to ensure that the geometric dimensions and elastic deformation of each contact are highly consistent. Stable positive force is a prerequisite for maintaining low and stable contact resistance and is also key to suppressing temperature rise fluctuations.5. Simulation Verification and Thermal-Electrical Coupling AnalysisDuring the design phase, engineers use finite element analysis software to perform electro-thermal coupling simulations: inputting parameters such as rated current, ambient temperature, and material properties to predict the temperature rise distribution in the contact area. By iteratively optimizing terminal shape, plating thickness, and assembly clearance, steady-state temperature rise is controlled within a safe threshold.The stamped metal contact piece in a battery connector, though only a few millimeters square, bears the crucial responsibility of efficient and safe energy transmission. Through a four-in-one system design encompassing materials, structure, process, and verification, modern contact pieces can effectively suppress temperature rise under the stringent requirements of high current, high density, and long lifespan, ensuring the reliability and safety of electrical connections. In the wave of electrification and intelligentization, this "tiny yet critical" component is continuously driving energy interface technology towards higher power density and better thermal management.
