Fabrication & Characterization of Thin-Film Solid State Metal Fluoride Batteries

Abstract

The increased proliferation of consumer electronics and electric vehicles has led to an exponential increase in the demand for lithium-ion batteries. Commercially used intercalation-based cathode materials in Li-ion batteries have relatively low capacity, high manufacturing costs, and sourcing / ethical concerns. Metal fluoride-based conversion cathodes promise unique benefits over these materials with regards to theoretical capacities, safety, supply, and cost. However, when built into full cells with liquid electrolytes, they have historically suffered side effects that lead to early cell degradation: poor ionic conductivity, volume swelling, resistance buildup, and morphological changes.

In this thesis, I will investigate a workaround of these symptoms by constructing an all solid-state architecture. The deliberate design of a liquid/polymer solvent-free cathode provides a more stable window by which to analyze cycling behavior and electrochemical performance. This defense focuses on the novel electrode and electrolyte fabrication methods used to achieve such a structure and associated characterization.