3D Printed Power Sources

Purpose and goal

The aim of this project is to 3D print an entire Lithium-Ion micro battery, i.e. electrodes, electrolyte, current collectors and encapsulation. To achieve this aim, three challenges were identified. One of the main challenges is rheological characterization of materials for battery components. The other two are designing a printing mechanism which can have better control over process parameters and identifying the right printable material for encapsulation and current collectors. We overcome these three primary challenges in this project and laid the foundation for future work.

Expected results and effects

The concentrations of electrode inks were adjusted to make the viscosity around 40Pa.s for printing electrodes. The viscosity number was based on rheological study. A heat curing based thermoset was used to print solid polymer electrolyte. One of the biggest challenges of the project is the printing mechanism and it has been solved using screw-based extrusion. PDMS gel was used to print encapsulation of battery. Graphene based filament was used to print current collectors. Successful printing of individual components of battery is encouraging and demonstrates future potential.

Planned approach and implementation

In WP1, elasticity and creep recovery testing in rheometer was done to measure the viscosity after the shear stress is removed. These tests helped us to evaluate the printability of inks. In WP2, a reliable, low cost and open source based printing mechanism for viscous inks was developed. It is one of the major achievements of this project. Using rheology, material formulations were developed in WP1. The printing mechanism developed in WP2 was used to print battery components in WP3. PDMS as an encapsulant and AROS graphene as current collector for 3D printed batteries was demonstrated.