Nickel and Cobalt — the Cathode Metals
One reshaped by a single country in under a decade, the other defined by a single mine district and a problem that cannot be engineered away.
Ore to Vehicle · Part 2 — The Metals · Chapter 7 · 19 min read
One metal reshaped by a single country in under a decade, and one defined by a single mine district and a problem that cannot be engineered away.
250 °C / 45 bar
HPAL autoclave conditions
>55 %
Indonesia’s share of world nickel
~75 %
DRC share of cobalt
0
Cobalt in an LFP cell
7.1 — Two ore types, only one ever easy
Sulfide ores — pentlandite in Russia, Canada and Australia — are straightforward: float, smelt, refine, exactly like copper. They are also largely depleted, with few new discoveries.
Laterite ores — the weathered nickel-bearing soils of Indonesia, the Philippines and New Caledonia — hold most of the world’s nickel and are hard. They come in two layers: limonite near the surface, low nickel and high iron, and saprolite below, higher nickel. Each needs a different process.
- •HPAL — high pressure acid leach, for limonite. Ore plus H₂SO₄ at 250 °C and 40–50 bar in a titanium-lined autoclave → Ni and Co into solution → precipitate as MHP → dissolve → solvent extraction → NiSO₄·6H₂O. Capital-intensive and historically a graveyard of cost overruns; Indonesian projects finally made it routine.
- •RKEF — for saprolite. Rotary kiln electric furnace → nickel pig iron, a low-grade Ni-Fe alloy for stainless steel.
- •Carbonyl — the Mond process, for extreme purity. Ni + 4 CO → Ni(CO)₄ at 50–60 °C, a volatile and extremely toxic liquid, then Ni(CO)₄ → Ni + 4 CO at 230 °C. Gives 99.99 % nickel pellets. A gas-phase separation, and chemically the most elegant step in this series.
7.2 — Class 1 versus Class 2
Important
Batteries need Class 1, above 99.8 per cent nickel and dissolvable into sulfate. Stainless steel is happy with Class 2. For years these were separate markets.
7.3 — The route that joined two markets
Technical framing
Since 2021: NPI + S → nickel matte → leach → NiSO₄. Converting a stainless-steel product into a battery product was the single change that reshaped the world nickel market — and it collapsed the price.
It is also why the LME nickel price and battery-grade nickel sulfate can now diverge or converge in confusing ways: two markets that used to be independent are now connected by a process route.
Indonesia now produces well over half the world’s nickel — an extraordinary concentration built in under a decade, on the back of an export ban on raw ore that forced processing onshore. It worked, and it is the most-cited policy precedent in every resource-holding country including India.
7.4 — Cobalt — a byproduct of a byproduct
Cobalt is almost never mined for itself. It comes out of the copper deposits of the DRC’s Katanga copperbelt, and increasingly out of nickel laterites in Indonesia. The DRC supplies around three-quarters of world production; China refines a similar share.
7.4.1 — The DRC route
Leach ore in H₂SO₄ → copper removed by SX-EW first → cobalt precipitated as Co(OH)₂, a roughly 30 per cent Co intermediate which is what actually ships. Then Co(OH)₂ + H₂SO₄ → CoSO₄ → solvent extraction to remove Ni, Mn and Fe → CoSO₄·7H₂O at battery grade.
Important
Artisanal mining is the part of this chain that cannot be engineered away. A meaningful minority of DRC cobalt is dug by hand, including by children, and it enters the same intermediate stream as industrial material. Traceability schemes exist and are imperfect.
This is the strongest non-technical argument for LFP, which contains no cobalt at all — and it is a large part of why LFP took the volume segment in India and China.
Quick check: test yourself
1.Why did nickel prices collapse after 2021?
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2.Why is HPAL so capital-intensive?
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3.What does choosing LFP remove from a supply chain, and what does it not?
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Chapter summary
- ✓Nickel sulfides are easy and depleting; laterites hold most of the world’s nickel and need HPAL for limonite and RKEF for saprolite.
- ✓Batteries need Class 1 nickel above 99.8 per cent; stainless steel is content with Class 2, and the two were separate markets for years.
- ✓Sulfiding nickel pig iron into matte joined those markets, reshaped world supply and collapsed the price — Indonesia built over half of world output in under a decade behind an ore export ban.
- ✓Cobalt is a byproduct of copper and nickel, three-quarters from the DRC, so its supply does not answer its own price.
- ✓Artisanal mining cannot be engineered away, and it is the strongest non-technical argument for cobalt-free LFP.
Frequently asked questions
What is the difference between Class 1 and Class 2 nickel?+
Class 1 is above 99.8 per cent nickel and can be dissolved into sulfate for batteries; Class 2, such as nickel pig iron, is fine for stainless steel. For years these were separate markets. Indonesia’s route of sulfiding NPI into matte and leaching it to sulfate joined them, which is why the LME nickel price and battery-grade nickel sulfate can now diverge or converge in confusing ways.
How did Indonesia come to produce over half the world’s nickel?+
By banning raw ore exports and forcing processing onshore, then commercialising two hard routes at scale — HPAL for limonite, which had historically been a graveyard of cost overruns, and RKEF followed by matte conversion for saprolite. It worked, it was built in under a decade, and it is now the most-cited policy precedent in every resource-holding country including India.
Why is cobalt described as a byproduct of a byproduct?+
Because it is almost never mined for itself. It comes out of the copper deposits of the DRC’s Katanga copperbelt and increasingly out of nickel laterites in Indonesia. The DRC supplies around three-quarters of world production and China refines a similar share. Since output is set by copper and nickel economics, cobalt supply does not respond to the cobalt price.
What is the artisanal mining problem, and what does it have to do with LFP?+
A meaningful minority of DRC cobalt is dug by hand, including by children, and it enters the same intermediate stream as industrial material. Traceability schemes exist and are imperfect. It is the part of this chain that cannot be engineered away, and it is the strongest non-technical argument for LFP — which contains no cobalt at all, and which took the volume segment in India and China partly for that reason.
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Ore to Vehicle is an original educational series on the battery and EV materials supply chain. Country shares, grades, prices and policy status are approximate, drawn from public reporting as of mid-2026, and move year to year — treat them as orders of magnitude rather than as a ledger, and verify before relying on them commercially.