8. August 2025 | Press releases:

New process makes lithium-ion batteries more economical Researchers at TU Braunschweig further develop electrode manufacturing process for industrial use

  • New process reduces energy consumption during drying of electrode coating
  • Enables higher product quality and storage stability as well as more flexible production
  • Development and scaling in collaboration with VARTA Coperion
  • Goal: industrial scaling

Lithium-ion batteries are a cornerstone of the energy transition – but they are complex and expensive to manufacture. As part of the ‘GranuGoIn’ project (‘Granulate-based semi-dry electrode manufacturing goes industrial’), a semi-dry manufacturing process for electrodes developed in a previous project is being significantly refined. The aim is to scale up the process for industrial application, both for anodes and cathodes.

Conventional production is based on a complex dispersion and coating process using liquid mixtures, which requires long drying times and high energy consumption. The new process developed by Technische Universität Braunschweig instead relies on granulate-based material that requires virtually no solvents. This eliminates large parts of the energy-intensive drying process – a key lever for reducing production costs.

In addition to the ecological and economic advantages, the new approach also offers technological improvements: the increased storage stability of the granulates enables more flexible, time-decoupled production and at the same time increases the quality of the electrodes produced.

With the ‘GranuGoIn’ project, TU Braunschweig is working with industry partners VARTA Microbattery GmbH and Coperion GmbH to bring the process to market maturity. A particular focus is on further developing the process parameters, optimising granulate dosing and integrating inline measurement technology for quality assurance during operation.

Storing energy for the future

Efficient and affordable batteries are crucial for the expansion of electromobility and for a stable power supply from renewable energies. The further development of corresponding manufacturing processes is therefore key to strengthening Germany as a centre of technology and business.

The ‘GranuGoIn’ project promotes knowledge transfer between science and industry and supports the establishment of a sustainable, competitive battery value chain in Germany.

Project details:

The joint project ‘Granulate-based semi-dry electrode manufacturing goes industrial’ (GranuGoIn) started on 1 January 2025 and will end on 31 December 2027. The project is coordinated by VARTA Microbattery GmbH, with partners including TU Braunschweig with its Institute for Particle Technology, VARTA Microbattery GmbH and Coperion GmbH, as well as associated partners Coperion K-Tron, Armor Battery Films and Matthews Int. Corp. The German Federal Ministry of Education and Research (BMFTR) is funding the GranuGoIn project with around €1.4 million.

About the Institute for Particle Technology

As the central institute of the Battery LabFactory Braunschweig (BLB), the Institute for Particle Technology (iPAT) has been working on process engineering issues for electrochemical storage technologies since 2007. The systematic investigation of the dispersion, coating and drying processes as a function of material and process parameters is one of iPAT’s core competencies. Product- and machine-related expertise is developed both practically and numerically in various research and industrial projects. The aim is to describe the influence of process control on the quality of battery electrodes through process-structure-property relationships. In addition to electrochemical characterisation, analytical methods for mechanical, electrical and structural layer properties are available for characterising the electrodes. Electrochemical characterisation is carried out at the BLB in single-compartment and multi-layer pouch cells of various sizes. This characterisation enables a final evaluation of the electrode structure. All of the analysis methods described are established at iPAT. Furthermore, iPAT has 10 years of experience in extrusion-based processes for the manufacture of LIB electrodes (Dreger et al. 2015; Dreger et al. 2019). The establishment of innovative plant technology is also part of iPAT’s expertise. Accordingly, production chains for solvent-free LIBs (LoCoTrop project) and all-solid-state batteries (FesKaBat project) have been developed, as well as solvent-reduced process chains based on direct coating in a calender and extrusion coating (HEMkoop and GranuProd projects).

About VARTA AG

VARTA AG manufactures and markets a comprehensive portfolio of batteries, ranging from micro batteries and household batteries to energy storage systems and customised battery solutions for a wide range of applications. Through intensive research and development, VARTA AG sets global standards in many areas of lithium-ion technology and microbatteries, making it a recognised innovation leader in the important growth markets of lithium-ion technology and primary hearing aid batteries. The VARTA AG Group currently employs around 4,000 people. With five production and manufacturing sites in Europe and Asia and sales centres in Asia, Europe and the USA, the operating subsidiaries of VARTA AG are currently active in over 100 countries worldwide.

About Coperion GmbH

Coperion is a global industry and technology leader in compounding and extrusion systems, size reduction, washing, separating, drying, and agglomeration, feeding, weighing, material handling and pneumatic conveying systems, as well as milling, mixing, thermal processing, dust collection and other services. Coperion develops, produces, and services plants, machinery, and components for the plastics and plastics recycling, chemical, battery, minerals, food and pharmaceutical industries. Coperion employs more than 5,000 people in its three divisions, Polymer, Food, Health & Nutrition, and Aftermarket Sales & Service – at over 50 sales and service locations worldwide. Coperion is an Operating Company of Hillenbrand (NYSE: HI), a global industrial company that provides highly-engineered, mission-critical processing equipment and solutions to customers serving a wide variety of industries around the world.