Date of Award

2020

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Graduate Group

Chemical and Biomolecular Engineering

First Advisor

Sue Ann Bidstrup Allen

Second Advisor

Mark Allen

Abstract

The reduction in size and the improvement in the capability of microsystems are presently limited by the size and the capacity of their on-board power supplies. A key performance metrics for the power supplies of microsystems is the capacity per footprint area, or areal capacity, in mAh/cm2, while the commercial 2D thin film micro-batteries possess low areal capacity of less than 0.2 mAh/cm2. Thus, it’s necessary to load battery components onto scalable 3D architectures to enable electrodes with high areal capacity. In this work, novel fabrication techniques are proposed. A facile high current hydrogen-templated electroplating technique is utilized to generate 3D porous microstructures, which serve as the scaffolds, current collectors, or even active materials for battery electrodes. In addition, electrochemical techniques and laser-machined substrate ensure uniform coating and high utilization of battery active materials to allow superior electrochemical performance. On the half-cell level, Si/NiSn composite anode deliver ultrahigh areal capacity over 40 mAh/cm2; and carbonate-compatible S cathode is developed and possess 4mAh/cm2 areal capacity with 85% capacity retention after 50 cycles at a high current density of 2.5 mA/cm2. On the full cell level, the micro-battery delivers an areal capacity of 3 mAh/cm2 with 2.3 mW/cm2 power density that meets the demands of many micro-electronic device. In addition, a proof-of-concept monolithic full cell based on polymer electrodeposition techniques is demonstrated to accelerate the cell manufacturing process. In conclusion, in this study, microelectronics-compatible fabrication of scalable, high surface area, and porous 3D metal network-based Li-ion micro-batteries is devised to enable electrodes with high areal capacity, high power density, manufacturability, low cost, and good safety performance.

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