Compound · LiCoO2

Lithium cobalt oxide

The cathode that made the lithium-ion cell possible in 1980, still in the phone in your pocket, and abandoned everywhere the pack is large.

Lithium cobalt oxide is the original lithium-ion cathode, and it is a rare case of a material that was right first time and has never been improved on for the job it does best.

John Goodenough identified it in 1980 at Oxford: a layered oxide that would give up its lithium at around four volts and take it back, reversibly, thousands of times. Every lithium-ion cell since is a variation on that idea, and it is why he shared the 2019 Nobel Prize at the age of ninety-seven.

It has the highest volumetric energy density of the common cathodes, which is exactly what a phone wants — the constraint there is millimetres of thickness, not grams. And it is a third cobalt by mass, thermally the least stable of the layered oxides, and good for only a few hundred cycles, which is why nothing with a large pack uses it.

So it survives in the smallest cells and nowhere else, which is an unusual endpoint for a founding material: not superseded, just confined.

History

Stanley Whittingham had shown intercalation worked at Exxon in the 1970s, using titanium disulfide and a lithium metal anode, and the lithium metal grew dendrites and shorted the cells.

Goodenough's contribution in 1980 was the cathode: a layered cobalt oxide that operated at roughly twice the voltage of the sulfide, which roughly doubled the energy available. Oxford declined to patent it and the rights went to the UK Atomic Energy Authority for a nominal sum, which is among the more expensive institutional decisions in materials history.

Akira Yoshino supplied the last piece in 1985 by pairing it with a carbon anode instead of lithium metal, which removed the dendrite problem and made a cell that could be sold. Sony did sell it, in 1991, into camcorders.

All three shared the 2019 Nobel Prize in Chemistry, and the nine-year gap between the cathode and the product is a fair illustration of how long a materials discovery takes to become a thing anyone can buy.

Medium confidence Weak evidence

How we know: 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.

is used in

Lithium-ion cell — object · in the smallest cells only — phones, laptops, cameras — where volume is the constraint and a few hundred cycles is a long enough life
Electronics manufacture — industry · phones, laptops and cameras — the applications where the constraint is millimetres of thickness rather than grams of mass
Smartphone — object · the cathode, and the small-cell chemistry: highest energy per unit volume, and a few hundred cycles is long enough for a phone

was succeeded by

NMC cathode — compound · everywhere the pack is large: substituting nickel and manganese for two thirds of the cobalt cut the cost and the supply exposure, and gave up some volumetric density that a car has room for and a phone does not

contains

Lithium — element · the working ion, and the material Goodenough showed could be taken out and put back at four volts
Cobalt — element · roughly a third by mass, which is why nothing with a large pack uses it
Oxygen — element · in layers, and released on overheating — LCO is the least thermally stable of the common cathodes

is sourced from

Cobalt — element · and a phone battery is a meaningful cobalt consumer per unit of energy stored, which the tonnages hide because the cells are small

is used as

Battery electrodes — application · the first cathode that worked, and still the highest volumetric energy density of the common ones

is an alternative to

Lithium iron phosphate — compound · opposite ends of every axis the choice runs on: LCO stores the most per unit volume and lasts a few hundred cycles, LFP stores the least and lasts thousands, and no application wants both

is produced by

Calcination — process · lithium carbonate and cobalt oxide fired together, which is the simplest of the cathode syntheses and part of why it was first

Sources

Material World
Our own writing
Wikidata
Wikimedia Foundation · Creative Commons CC0 1.0 Universal (public domain dedication)

Questions this page answers

Where it comes from, and what it becomes

Follow Lithium cobalt oxide 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

Lithium cobalt oxide → is sourced from (and a phone battery is a meaningful cobalt consumer per unit of energy stored, which the tonnages hide because the cells are small) → 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
Lithium cobalt oxide → is produced by (lithium carbonate and cobalt oxide fired together, which is the simplest of the cathode syntheses and part of why it was first) → 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
Lithium cobalt oxide → is produced by (lithium carbonate and cobalt oxide fired together, which is the simplest of the cathode syntheses and part of why it was first) → Calcination → takes as input (supplies the silica and alumina that combine with lime in the cement kiln) → Clay → is sourced from (clay is chiefly what feldspar becomes when it weathers) → Orthoclase
Lithium cobalt oxide → is produced by (lithium carbonate and cobalt oxide fired together, which is the simplest of the cathode syntheses and part of why it was first) → Calcination → takes as input (at around 150 °C, which is driving off water rather than decomposing a carbonate — so no carbon dioxide comes out of the rock) → Gypsum plaster → is sourced from (calcined to drive off three quarters of the water, and it takes it back when mixed) → Gypsum
Lithium cobalt oxide → is produced by (lithium carbonate and cobalt oxide fired together, which is the simplest of the cathode syntheses and part of why it was first) → Calcination → takes as input (gently calcined to plaster of Paris, a far lower temperature than lime burning) → Gypsum
Lithium cobalt oxide → is produced by (lithium carbonate and cobalt oxide fired together, which is the simplest of the cathode syntheses and part of why it was first) → Calcination → takes as input (heated until the carbonate decomposes to lime and carbon dioxide) → Limestone → is composed of → Calcite

These are the most distinct paths back. Lithium cobalt oxide can be traced through others besides.

Downstream — what it becomes

Lithium cobalt oxide → is used in (in the smallest cells only — phones, laptops, cameras — where volume is the constraint and a few hundred cycles is a long enough life) → Lithium-ion cell → is used in (and portable computing came first by two decades) → Electronics manufacture → is associated with (and the supply chain it produced is the deepest and most concentrated in the world economy) → The semiconductor era complete chain
Lithium cobalt oxide → is used in (the cathode, and the small-cell chemistry: highest energy per unit volume, and a few hundred cycles is long enough for a phone) → Smartphone → is used in (and it is where four separate raw-material arguments meet — the 3TG conflict minerals, cobalt, the rare earths, and everything too dispersed to recover) → Electronics manufacture → is associated with (and the supply chain it produced is the deepest and most concentrated in the world economy) → The semiconductor era complete chain
Lithium cobalt oxide → is used in (phones, laptops and cameras — the applications where the constraint is millimetres of thickness rather than grams of mass) → Electronics manufacture → is associated with (and the supply chain it produced is the deepest and most concentrated in the world economy) → The semiconductor era complete chain
Lithium cobalt oxide → is used as (the first cathode that worked, and still the highest volumetric energy density of the common ones) → Battery electrodes
Lithium cobalt oxide → is used in (the cathode, and the small-cell chemistry: highest energy per unit volume, and a few hundred cycles is long enough for a phone) → Smartphone → is associated with (the object the whole period arrives at, and the one that put roughly sixty elements into a pocket) → The semiconductor era complete chain
Lithium cobalt oxide → is used in (in the smallest cells only — phones, laptops, cameras — where volume is the constraint and a few hundred cycles is a long enough life) → Lithium-ion cell → is used in (grid storage and electric vehicles, which is what turned a list of obscure elements into a geopolitical argument) → Energy generation

These are the most distinct paths onward. Lithium cobalt oxide ends up in others besides.