UC Santa Cruz

Electrochemical energy technologies are essential for enabling the global transition toward sustainable energy systems by supporting renewable energy integration, transportation electrification, and portable electronics. Despite significant advances in electrode materials, the performance of electrochemical devices remains fundamentally constrained by interfacial reaction kinetics, transport limitations, and nonuniform electrochemical processes that become increasingly pronounced under practical operating conditions. These challenges motivate the development of new design strategies that extend beyond materials discovery toward engineering the electrochemical environment in which reactions occur.This dissertation demonstrates that electrochemical interface engineering and rational structural design provide complementary approaches for regulating electrochemical reactions across fundamental chemistry and device-level applications. By tailoring interfacial thermodynamics, local reaction environments, and electrode architectures, electrochemical reactions including charge and ion transfer, materials nucleation and growth, and phase transformation can be fundamentally controlled to improve both electrochemical energy storage and electrochemical materials manufacturing.The first part of this dissertation investigates electrochemical interface engineering in earth-abundant manganese-based (Mn-based) electrochemical systems. Interfacial proton activity and water activity are regulated through electrolyte design to enhance the operating voltage and energy efficiency of the Mn2+/MnO2 conversion reaction. Dynamic interfacial redox mediation is subsequently introduced to stabilize the local interfacial environment, suppress unfavorable reaction pathways, and improve the reversibility of Mn2+/MnO2 conversion. Extending these concepts to electrochemical materials manufacturing, interfacial thermodynamics are engineered to direct MnO2 nucleation during electrodeposition, transforming diffusion-limited growth into reaction-limited progressive nucleation and enabling dense, conformal MnO2 coatings with ultrahigh mass loadings throughout complex porous scaffolds. The influence of nanoscale MnO2 thickness on electrochemical behavior is further investigated to establish relationships among film thickness, reaction kinetics, and charge-storage mechanisms. Additional studies demonstrate the application of interface engineering to non-aqueous lithium metal batteries, lithium-ion hybrid capacitors and dendrite-free zinc metal anodes with 100 % utilization rate, illustrating the broad applicability of interfacial design principles across diverse electrochemical systems.The second part of this dissertation focuses on rational structural design through architected three-dimensional (3D) electrodes. Interpenetrated electrode architectures fabricated by additive manufacturing are developed to overcome the transport limitations associated with conventional planar devices. By reducing ion diffusion distances while maintaining low tortuosity, these structures enable improved reaction kinetics, enhanced device volumetric energy density, and superior electrochemical performance under demanding operating conditions including low temperatures.Importantly, this dissertation demonstrates that electrochemical interfaces and electrode architectures are intrinsically coupled rather than independent design parameters. Throughout the studies presented herein, interface engineering is integrated with rationally designed 3D structures to achieve uniform electrochemical reactions, efficient charge and ion transport, controlled materials synthesis, and scalable device architectures. Together, these findings establish a general framework for integrating electrochemical interface engineering with rational architecture design, providing new opportunities for advancing next-generation electrochemical energy storage technologies and electrochemical materials manufacturing.