# Electrochemistry Electrochemistry is the study of reactions that move electrons through an external circuit rather than directly between molecules. Separate the two halves of a [[Redox]] reaction, connect them with a wire and an electrolyte, and the electron transfer becomes usable [[Electric_current|current]] at a measurable [[Voltage]]. ## One framework, three devices A [[Battery_(electricity)|battery]] carries its reactants inside and runs down; a [[Fuel_cell]] is fed continuously and does not; an electrolyser is either one driven backwards by [[Electrolysis]]. All three are described by the same cell potential, the same overpotential losses, and the same transport limits — reactants must reach the electrode, which makes this a [[Diffusion]] and [[Fluid_dynamics|flow]] problem as much as a chemical one. [[Corrosion]] is the same physics happening uninvited, which is why [[Reliability_engineering|corrosion control]] and battery design are taught from one theory. **Reads with:** *Electrolysers, Fuel Cells and Batteries: Analytical Modelling (2024)* — [OTL record](https://open.umn.edu/opentextbooks/textbooks/electrolysers-fuel-cells-and-batteries-analytical-modelling) · [download](https://books.open.tudelft.nl/home/catalog/book/176). Seeded from the Thury Hydrodynamics Apex Spine book shelf. **On the spine:** [[Electrolysis]] · [[Fuel_cell]] · [[Battery_(electricity)]] · [[Redox]] · [[WT!Thury_Hydrodynamics_Compendium]]. ## Wikipedia : Wikitube **Strict pair:** [Wikipedia](https://en.wikipedia.org/wiki/Electrochemistry) : [Wikitube](https://en.wikitube.io/wiki/Electrochemistry) ## Previous hub tags Hubs: `Life_Physics`, `Systems`. Portals: [[PORTAL_Thury_Hydrodynamics_Apex_Spine]], [[PORTAL_Energy]], [[PORTAL_Hydrogen]]. --- *Apex Spine wave · 2026-09-10 · stub · microsim layer deferred.*