In recent decades, approaches to generate electrical energy through renewable means has greatly benefited from technological advancements. However, the need for robust schemes to store that energy in safe and cost-effective manners persists. Thus, there is a shared global call to advance electrical energy storage science and technology. Breakthroughs in the field stand to impact humans, ecosystems, environments, economies, and even international security. Currently, many innovative routes rooted in basic science are being taken to develop novel concepts, chemistries, electrolytes, and geometries for electrical energy storage. Many of these approaches make use of nano-to-mesoscale structures and technologies which increases the demand for new methods of characterization and scientific discovery at those scales. Still, progress to address this demand is stymied by practical scientific and technological challenges associated with the buried interfaces in battery systems.

In this dissertation, I present how my PhD work has precisely targeted this need within the energy storage community, and made lasting impact. I detail why, and how, I have pioneered scanning-probe based technologies and techniques that make use of "battery probes" consisting of electrochemically active materials. A suite of techniques is developed and leveraged for basic electrical energy storage science: scanning nanopipette and probe microscopy, pascalammetry with microbattery probes, inverted scanning tunneling spectroscopy, and nanoscale solid-state electrochemistry with nanobattery probes. The use of these techniques motivated finite-element numerical simulations of electrostatic potentials, and electric fields, at play during field-driven lithiation of multi-walled carbon nanotubes. Also motivated were analytical models for surface diffusion and diffusion through a stressed electrolyte simultaneously experiencing latent-species activation.