Industry
Energy Technology & Advanced Materials – Sintering Furnaces and Pyrolysis
Battery cells, fuel cells, high-performance ceramics and carbon fibres are manufactured through thermal processes demanding the highest precision. NTH Therm high-temperature furnaces and pyrolysis furnaces are designed for these future materials.
Thermal Processes for Energy Technology and Future Materials
The energy transition creates new demands on thermal processes. Battery cells, fuel cells, solid-state electrolytes and high-performance ceramics cannot be manufactured without precise heat treatment. At the same time, a new industry is emerging for the recycling of energy storage devices — also dependent on thermal processes.
NTH Therm high-temperature furnaces, tube furnaces and pyrolysis furnaces cover the key processes of energy technology and advanced materials.
Battery Cathode Materials – Precision in the Sintering Kiln
The active cathode materials of modern lithium-ion cells are synthesised and sintered through high-temperature reactions between precursors. The sintering process largely determines the battery’s capacity, cycle life and safety behaviour.
LFP – Lithium Iron Phosphate (LiFePO4) Sintering temperature: 600–800 °C, atmosphere: reducing or neutral (N2 + H2 or pure N2). LFP is thermally more stable than other cathode materials and is sintered at lower temperatures.
NMC – Lithium Nickel Manganese Cobalt Oxide Sintering temperature: 700–900 °C, atmosphere: oxygen-rich. The exact NMC stoichiometry (111, 622, 811) significantly influences sintering temperature and atmosphere. NMC 811 is particularly sensitive to atmosphere deviations.
NCA – Lithium Nickel Cobalt Aluminium Oxide Sintering temperature: 700–800 °C, atmosphere: oxygen. Similar requirements to NMC.
For these processes, TH1 tube furnaces (small batches, research) and ICF chamber furnaces (scale-up, pilot production) with precise gas management and atmosphere control are suitable.
Solid-State Electrolytes – Key Material of the Battery Future
Ceramic solid-state electrolytes are the key to safer and more energy-dense next-generation batteries. The sintering process is demanding:
LLZO (Lithium Lanthanum Zirconate Oxide) Sintering temperature: 900–1200 °C, atmosphere: oxygen or controlled Li atmosphere (Li evaporation must be compensated). The sintering process requires highly precise temperature control and careful atmosphere management.
NASICON-Type Electrolytes (LATP, LAGP) Sintering temperature: 900–1100 °C. Less sensitive than LLZO, but atmosphere control remains important.
Fuel Cells – Sintering of Electrodes and Electrolytes
Solid Oxide Fuel Cells (SOFC) The electrolyte (YSZ – yttria-stabilised zirconia) is sintered at 1300–1500 °C. Electrodes (cathode: LSC, LSCF; anode: Ni/YSZ cermet) at 1000–1200 °C. Very high demands on temperature uniformity and process atmosphere. NTH Therm ICF chamber furnaces with up to 1300 °C are suitable for these processes.
PEM Fuel Cells For the catalyst support (platinum particles on carbon) and membrane components, tempering and activation annealing at 200–400 °C under protective gas are used.
High-Performance Ceramics and Composites
Silicon carbide (SiC): for power semiconductors, heat exchangers and protective equipment: sintering temperature 1800–2200 °C (outside NTH Therm standard range, but ICF furnaces usable for pre-sintering and special applications to 1300 °C).
Aluminium oxide (Al2O3): for substrates, insulators, cutting ceramics: sintering temperature 1400–1700 °C. ICF furnaces configurable.
Boron nitride, silicon nitride: for special applications in power electronics and thermal management.
Battery Recycling – Pyrolysis as a Key Step
Recycling of lithium-ion batteries requires a thermal preparation step: pyrolysis (also known as the thermal pyrolysis or black-mass process). Before hydrometallurgical recovery of Li, Co, Ni, Mn and Cu, the organic components — electrolyte, binder, separator — are thermally decomposed:
- Temperature range: 400–600 °C
- Atmosphere: inert gas (N2) or slightly reducing
- Exhaust treatment: required (electrolyte vapours, HF formation)
NTH Therm pyrolysis furnaces are specifically developed for this process — with sealed chambers, inert gas management, integrated exhaust treatment and the necessary safety equipment for handling lithium-ion cell materials.
Frequently Asked Questions
What sintering temperatures are typical for lithium-ion cathode materials?
LFP (LiFePO4): 600–800 °C. NMC (LiNiMnCoO2): 700–900 °C. NCA (LiNiCoAlO2): 700–800 °C. All processes require precise atmosphere control — LFP under inert gas (N2/Ar), NMC/NCA frequently under oxygen atmosphere. TH1 tube furnaces and ICF chamber furnaces are configurable for these requirements.
How does pyrolysis work in battery recycling?
In the pyrolysis process (also called the black-mass process), discharged and mechanically prepared lithium-ion cells are thermally treated at 400–600 °C under exclusion of oxygen. Organic electrolyte components and binders are thereby decomposed. The result is 'black mass' — a mixture of cathode active material, graphite and metal foil for hydrometallurgical further processing.
What atmospheres are needed for solid-state electrolyte sintering?
Ceramic solid-state electrolytes (e.g. LLZO – lithium lanthanum zirconate) are sintered at 900–1200 °C, often under oxygen atmosphere with Li vapour suppression (MgO capsules) or under precisely controlled atmosphere. NTH Therm TH1 tube furnaces with gas supply are suitable for these demanding atmospheres.
Can NTH Therm supply furnaces for carbon fibre carbonisation?
The carbonisation line for carbon fibres operates at 1000–1500 °C and requires continuous furnaces under inert gas atmosphere (N2). NTH Therm conveyor furnaces can be designed for these processes. Graphitisation at 2000–3000 °C is outside NTH Therm's standard range, but we are happy to advise on system selection.