The Need

Advanced lithium-ion batteries increasingly adopt metallized polymer current collectors to improve safety by mitigating internal short circuits and thermal runaway. However, these collectors are inherently difficult to join to each other and to battery tabs using conventional manufacturing methods. Existing approaches, such as ultrasonic metal welding alone, often yield mechanically weak and electrically inconsistent joints, limiting manufacturing yield, scalability, and industry adoption of this safer current collector technology.

The Technology

OSU engineers have developed a reliable joining method for metallized polymer current collectors and battery tabs using ultrasonic-assisted soldering and/or ultrasonic conductive adhesive bonding. By leveraging ultrasonic energy to promote controlled flow and wetting of a conductive interlayer, the approach creates repeatable, mechanically robust, and highly conductive joints without compromising the polymer substrate. The method is compatible with multi-layer stacks and can be implemented using manufacturing-relevant ultrasonic equipment.

Commercial Applications

• Lithium-ion battery manufacturing for electric vehicles and energy storage systems
• Consumer electronics and aerospace batteries requiring enhanced safety

Benefits/Advantages

• Improved joint reliability: Consistent electrical conductivity and mechanical strength versus ultrasonic welding alone
• Enables safer batteries: Facilitates adoption of self-protecting metallized polymer current collectors
• Manufacturing-compatible: Uses scalable ultrasonic processes and low-cost solders or adhesives
• Design flexibility: Supports single- or multi-layer current collector stacks and diverse tab materials