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Material World
Application

Battery electrodes

Storing and releasing electrical energy by moving ions between two electrodes.

A rechargeable cell works by shuttling ions between two electrodes through an electrolyte. The materials chosen set almost everything that matters: how much energy the cell holds per kilogram, how fast it can be charged, how many cycles it survives, and how badly it behaves when damaged.

The field is a sustained search for electrode materials that are simultaneously light, abundant, stable and cheap — a combination no known chemistry fully satisfies.

Medium confidence Weak evidence checked recently · only one source, so there is nothing to cross-check it against · stated directly by the source

How this connects

Where a connection has been confirmed by an outside reference, that reference is named beside it.

uses

  • Cobalt — element · stabilises the cathode structure
  • Lithium — element · the defining material of the rechargeable cell
  • Nickel — element · higher nickel content buys energy density at some cost in stability
  • Lead — element · lead-acid cells, which account for most lead consumption and are heavily recycled
  • Pyrolusite — mineral · manganese dioxide is the cathode of the zinc-carbon and alkaline cells
  • Mischmetal — alloy · the negative electrode of the nickel-metal hydride battery, which powered hybrid vehicles and portable electronics before lithium-ion displaced it
  • Lithium-ion cell — object · the object the application exists for
  • Lithium iron phosphate — compound · as the cathode, and it took the majority of world cell production in about five years on cost and safety rather than on performance
  • NMC cathode — compound · as the high-energy cathode — the one that buys kilometres per kilogram and pays for them in supply risk
  • Lithium cobalt oxide — compound · the first cathode that worked, and still the highest volumetric energy density of the common ones
  • Battery graphite — material · as the anode of essentially every lithium-ion cell there is, and the largest single material input to the industry by mass

Sources

  • Material World
    Our own writing

Questions this page answers

Where it comes from, and what it becomes

Follow Battery electrodes back to what it starts as, and forward into what it becomes. Each step is a documented one — a real route material takes, not a chain of inference.

Upstream — what it comes from

  • Battery electrodes → uses (stabilises the cathode structure) → Cobalt → is sourced from (much of world supply arrives as a by-product of copper mining rather than from cobalt-first operations) → Copper → is produced by (as blister copper, refined electrolytically afterwards) → Smelting → takes as input (as the element removed, not added) → Oxygen → is produced by (the largest output by tonnage, and the reason air separation units sit beside steelworks) → Air separation
  • Battery electrodes → uses (the defining material of the rechargeable cell) → Lithium → is produced by (the majority of world supply, concentrated over a year or more in ponds on the Andean salars from a few hundred parts per million to a few per cent) → Brine evaporation → takes as input (and the pond sequence is run so that the less soluble salts crystallise out first, leaving the sodium chloride to be harvested on its own) → Salt → is sourced from (by solar evaporation, which needs a dry sunny coast and is the cheapest route there is) → Seawater → is composed of (about 96.5 per cent by mass — seawater is 3.5 per cent dissolved solids and the rest of it is this) → Water
  • Battery electrodes → uses (higher nickel content buys energy density at some cost in stability) → Nickel → is produced by (reduced from roasted pentlandite concentrate, with the platinum-group metals following into the refinery) → Smelting → takes as input (as the element removed, not added) → Oxygen → is produced by (the largest output by tonnage, and the reason air separation units sit beside steelworks) → Air separation → takes as input (the feedstock, and an unusual one in being free, unlimited and available anywhere — the cost is entirely the energy to liquefy it) → Air
  • Battery electrodes → uses (the negative electrode of the nickel-metal hydride battery, which powered hybrid vehicles and portable electronics before lithium-ion displaced it) → Mischmetal → is composed of (as ferrocerium, the lighter flint — the iron is what lets a steel wheel shave sparks off it) → Iron → is produced by (as pig iron, high in carbon and brittle until refined) → Smelting → takes as input (as the element removed, not added) → Oxygen → is produced by (the largest output by tonnage, and the reason air separation units sit beside steelworks) → Air separation
  • Battery electrodes → uses (the object the application exists for) → Lithium-ion cell → is made of (in the cathode of the older chemistries, and the component the industry has been designing away from) → Cobalt → is sourced from (much of world supply arrives as a by-product of copper mining rather than from cobalt-first operations) → Copper → is produced by (as blister copper, refined electrolytically afterwards) → Smelting → takes as input (roasted to drive off sulfur, then reduced to copper) → Chalcopyrite
  • Battery electrodes → uses (as the cathode, and it took the majority of world cell production in about five years on cost and safety rather than on performance) → Lithium iron phosphate → is produced by (lithium, iron and phosphate precursors fired together under an inert atmosphere, with a carbon source that leaves the conductive coating each particle needs) → Calcination → takes as input (heated until the carbonate decomposes to lime and carbon dioxide) → Limestone → is sourced from (precipitated from it, mostly by organisms building shells and skeletons out of dissolved calcium and carbonate) → Seawater → is composed of (about 96.5 per cent by mass — seawater is 3.5 per cent dissolved solids and the rest of it is this) → Water

These are the most distinct paths back. Battery electrodes can be traced through others besides.