Sodium-Ion Batteries Explained: The Ion That's Bigger AND Smaller Than Lithium

Sodium is a thousand times more abundant than lithium and far cheaper — so why isn't it in your phone? In this lecture we build a sodium-ion battery from an empty whiteboard, one honest constraint at a time: we pick the ion, the anode, the current collectors, the electrolyte, and the cathode — then judge it against lithium on the numbers that actually matter. Every figure on screen is real and sourced; every simulation is generated, not cartooned (PyBaMM, real crystal structures, honest KPIs). No hype — sodium loses on energy density and wins on cost, abundance, safety, cycle life, and cold performance. Here's exactly why. ⏱ CHAPTERS 0:00 The $200 puzzle 1:18 Part 1 · Why sodium 4:07 Part 2 · The physics bill 6:21 Part 3 · The anode 9:20 Part 4 · The collectors 10:58 Part 5 · The electrolyte 12:17 Part 6 · The cathode 16:42 Part 7 · The scorecard 20:25 Part 8 · The verdict 📌 What you'll learn: • Why sodium-ion batteries exist — abundance, cost, and the lithium supply chain • How a sodium cell actually works, built component by component • Why graphite fails for sodium (it's the bond, not the size) and how hard carbon fixes it • The three cathode families: layered oxide, polyanionic (NVPF), and Prussian blue • An honest sodium-vs-lithium scorecard: energy density, cost, cycle life, and −40 °C performance Subscribe for honest, simulation-driven battery science — every number real, every claim checked. #sodiumion #battery #batteries #energy #science #cleanenergy #electrochemistry