What temperature is used to pyrolyse lithium-ion batteries?

Electrolyte solvents are removed at about 100–300 °C. PVDF binder is decomposed at about 500–700 °C. Carbothermal reduction of NMC/NCA black mass is typically 550–630 °C under nitrogen.

How much lithium is recovered after battery pyrolysis?

Water leaching after ~600 °C pyrolysis has given about 63% lithium from NCA cells and from reductant-free NMC black mass at near-neutral pH, versus about 21% without pyrolysis. Acid or oxalate steps can exceed 97% lithium.

Lithium-ion battery pyrolysis and black mass

Direct answer

What does pyrolysis do in battery recycling?

It is a safety and liberation step. You are not making diesel. You are (1) taking out flammable electrolyte, (2) decomposing PVDF so cathode powder lets go of foil, (3) optionally reducing layered oxides so lithium becomes water-soluble as Li₂CO₃/Li₂O, and (4) sending fluorine to a scrubber. The solid that remains is black mass.

Two industrial schools

	Kiln / rotary pyrolysis	Vacuum drying (Duesenfeld-class)	Smelting (Umicore-class)
Temperature	450–700 °C (after optional 100–300 °C dry)	low T, reduced pressure	>1000–1500 °C
HF	Yes from LiPF₆ + PVDF unless dry/inert/scrubbed	Designed to avoid HF; recover solvent	Fluorine to off-gas / slag
Lithium	Can become water-leachable (~63% in 2026 papers)	Stays in BM for hydro	Mostly lost to slag
Graphite / LFP	Preserved if T not excessive	Preserved	Graphite burned; LFP poor fit
Product	Pyrolysed black mass	“Black” without thermal binder kill	Cu–Ni–Co alloy + slag

Temperature and lithium numbers that are actually published

Electrolyte: thermal treatment ~100–300 °C to drop organic solvents. Gas production from 1 M LiPF₆ + EC/DMC/DEC accelerates above ~180 °C; main gases CO₂, H₂, CO (~80%).
PVDF: multi-stage 420–540 °C, E_α ~200 kJ/mol. Fluorinated organics in oil peak ~500 °C. Industrial lines often 450–550 °C for 1–3 h under N₂, then lime scrub: 2 HF + Ca(OH)₂ → CaF₂.
NCA cylindrical cells, Ar, 500–900 °C: optimum 600 °C / 120 min → 63.6% Li by water leach (J. Sustainable Metallurgy 2026).
NMC black mass, no added reductant, 550–630 °C / 60 min N₂: ~63% Li at pH ~7 vs 21% untreated; Ni/Co/Mn dissolution 1–6% (Waste Management 2026).
Oxalic leach of industrial pyrolytic black powder: 97.35% Li, Ni/Co ~0, Fe 16%, Mn 10% at optimised RSM conditions (JECE 2025).
Infrared rapid pyrolysis + reductant gas: reported 98% lithium extraction in a 2025 Green Chemistry paper — lab, not a plant guarantee.
LFP, open-air 650 °C / 15 min with casing: 72–74% LFP recovery to <300 µm BM; flotation >85% LFP at >95% grade (J. Cleaner Production 2026). Casing limited pO₂ and protected copper.

What black mass is

There is no single composition. GB/T 45203-2024 is China’s attempt to standardise recycled black mass. Real BM is NMC or LFP or a blend, plus graphite, residual F, Cu/Al fines if milling was wet or oxidative. ACS Omega 2025 showed industrial pyrolysed BM contains high-T reaction products you will not see in a synthetic NMC powder. Model the incoming chemistry or the hydro plant will lie to you.

How to manage a battery pyrolysis line

Discharge (seawater is used in papers; industrial prefers controlled resistors).
Inert shred or whole-cell thermal — pick one and design explosion relief either way.
Decide vacuum dry vs kiln. Vacuum if you want solvent back and no HF. Kiln if you need PVDF gone and carbothermal Li.
N₂ or self-generated reducing gas. Measure O₂.
HF/POF₃/fluorocarbon scrub + baghouse. Never vent pyrolysis gas.
Cool BM under inert before air. Hot carbon + air is a fire.
Then hydro or direct recycle. Pyrolysis is not the money step.

PVDF and LiPF₆ are also fluorine chemistry → PFAS/TFA page