Demand for high-performance lithium-ion batteries is growing rapidly
A key challenge in cell manufacturing is the precise, reproducible, and material-friendly lamination of battery components.
The isobaric double belt press from HELD provides ideal process conditions for this: constant pressure distribution, controlled temperature management, and continuous production. This technology demonstrates enormous potential, particularly when laminating separators, electrode-separator laminates (ESL), and complete cell stacks (mono-cells).
The role of lamination in lithium-ion cell manufacturing
In lithium-ion battery production, cells typically consist of the components anode, separator, and cathode.
Typical advantages of isobaric lamination compared to conventional processes:
Improved contact between electrode and separator
Higher mechanical stability
High-precision lamination
Separator Lamination in Lithium-Ion Batteries
The separator is a microporous polymer membrane that electrically separates the anode and cathode while allowing lithium ions to pass through.
Typical separator materials:
PE/PP microporous
Reinforced non-woven separators (e.g. aramid or ceramic)
Typical process parameters – Temperature:
PE/PP separator: 90–110 °C
Reinforced non-woven: 100–130 °C
Typical process parameters – Pressure:
PE/PP: 10–40 bar
Non-woven: 20–60 bar
Importance of lamination
Laminating a separator alone is usually not practical. The greatest added value is achieved when laminating it together with an electrode.
Advantages: improved handling during production, a more stable electrode-separator interface, higher stacking accuracy, and reduced wrinkle formation.
For reinforced non-woven separators, pre-lamination can still be beneficial in order to planarize the material and improve stability.
The active materials of the battery are first coated onto metal foils.
Typical anode materials: graphite, hard carbon / soft carbon, silicon, titanium oxide. These materials are applied to copper foil.
Typical cathode materials: LCO, NMC, NCA, LMO, LFP. These are coated onto aluminum foil.
Lamination does not take place at the material level, but at the electrode or cell stack level.
Electrode-Separator Laminate (ESL)
An important step in modern battery factories is Electrode-Separator Lamination (ESL), where an electrode is laminated directly with a separator.
Structure
Anode-ESL: Anode + Separator
Cathode-ESL: Cathode + Separator
Typical process parameters – Temperature:
90–110 °C
Typical process parameters – Pressure:
20–50 bar
For a material thickness of approx. 50–200 µm
Advantages of ESL: significantly improved handling, higher positioning accuracy during stacking, modular cell manufacturing, and a considerably lower reject rate. Research conducted together with RWTH Aachen University shows that ESL lamination can be a decisive step for high-speed stacking lines.
Advantages of Lamination Using the Isobaric Process
Homogeneously compacted cell stack
Reduced internal voids
Improved mechanical stability
Stable and reproducible cell performance
Thanks to uniform pressure across the entire belt width, the double belt press is particularly suitable for large-format battery cells.
HELD – Your Partner for Innovative Manufacturing of Lithium-Ion Batteries
HELD systems ensure consistently high quality in lithium-ion and solid-state batteries, which is essential for industrial applications. Precise temperature and pressure distribution across the entire material web enables homogeneous material properties, high reproducibility, and minimal tolerances in thickness, density, and surface quality.
Request your free sample production now!