Methods for the manufacture of flexible microbatteries
Designs, strategies and methods for forming micro-batteries are described. In some examples, ultrasonic welded seals may be used to seal battery chemistry within the micro-battery. In some further examples, the micro-battery is encapsulated by a copper film where at least a portion of the copper film is formed by electroless plating.
1. A method of manufacturing a micro-battery comprising:
obtaining a cathode collector;
attaching a cathode to the cathode collector with a conductive adhesive;
obtaining an anode collector;
obtaining an anode;
stacking the cathode collector, the cathode, the anode, the anode collector, and a separator, wherein the separator lies between the cathode and the anode;
surrounding the stack with a first and second flexible plastic sheet;
welding the first and second flexible plastic sheets to each other with a first ultrasonic weld, wherein the first ultrasonic weld surrounds the stack along a first portion of two sides, wherein a second portion of the two sides comprises a fill port for the micro-battery;
filling an electrolyte within the fill port;
applying a second ultrasonic weld, wherein the second ultrasonic weld seals the second portion of the two sides of the first and second flexible plastic sheets and seals the fill port;
depositing an electroless plated layer of copper along a portion of the micro-battery.
2. The method of claim 1 wherein ultrasonic motion applied during at least one of the first ultrasonic weld and the second ultrasonic welds occurs predominantly along the same plane as the surface being sealed.