How to Set Up a Coin Cell Laboratory Line for Battery Research

TOB New Energy Technology Co., Ltd., a leading provider of equipment and integrated solutions for lithium-ion, sodium-ion, and other battery research applications, has released a comprehensive guide on setting up a coin cell laboratory line. This guide is essential for research teams aiming to screen new cathode and anode materials, compare binders, conductive additives, solvents, and electrode formulations, and evaluate various processing parameters.

The coin cell laboratory line, typically positioned between material development and larger-scale cell production, serves multiple purposes. It is particularly useful for laboratories that need to screen new materials, compare different formulations, study separators and electrolytes, and build lithium-metal half-cells or full cells for early electrochemical testing. The line is also valuable for generating repeatable data before investing in larger-scale equipment and training operators.

The most common formats for coin cells are CR2016, CR2025, and CR2032. A standard half-cell typically includes a coated working electrode, a separator, and a lithium-metal counter electrode. Depending on the research objective, the same general workflow can be adapted for full cells, sodium-ion cells, or reusable split test cells.

A complete coin cell laboratory line is normally divided into five connected areas: material preparation, electrode preparation, dry-room or glove-box assembly, sealing, and testing. The process flow and the relationship between materials and parameters are critical to ensure consistency and repeatability.

Material Preparation and Drying The basic equipment required for material preparation and drying includes a precision balance for accurate formulation weighing, a vacuum drying oven for active materials, conductive agents, binders, electrodes, and separators, and storage containers and trays suitable for dry or inert-atmosphere handling. Material drying should be planned around the material rather than a single universal temperature. Conductive agents, polymer binders, cathode powders, and anode powders may require different drying conditions. The material supplier's specification, the solvent system, and the laboratory's own moisture measurements should be used to define the final recipe.

Slurry Mixing and Inspection A laboratory vacuum planetary mixer is the central machine in this station. It should provide controlled mixing speed, adjustable mixing time, temperature monitoring, and vacuum operation. Small working volumes are often sufficient for early-stage screening, while larger vessels are useful when a laboratory is comparing several formulations in one campaign. Depending on the research programme, the station may also include a slurry filter, a slurry transfer device, a viscosity tester, a solid-content measurement setup, and a particle-size or dispersion inspection method.

Coating and Electrode Drying The electrode preparation section normally includes a laboratory blade coater or film applicator, a heated coating bed, interchangeable doctor blades or coating heads, a vacuum drying oven or controlled drying chamber, and a thickness gauge and balance for coating inspection. A blade coater is often adequate for material screening and formulation comparison. A slot-die or more automated coating system becomes more attractive when the laboratory is developing a process intended for pilot-scale transfer.

Calendering and Disc Cutting After drying, the electrode may need to be compacted with a laboratory roller press. The roller press should provide stable gap control and repeatable pressure. The correct setting depends on the electrode chemistry, loading, porosity target, and desired electrolyte wetting behavior. The disc-cutting station normally includes a manual or pneumatic electrode disc cutter, interchangeable punching dies for the selected coin cell format, a separator cutter or compatible cutting tool, an inspection microscope or magnifier, and trays for sorting good discs from discs with burrs, cracks, or coating defects.

Glove Box, Electrolyte Filling, and Coin Cell Sealing Cell assembly is normally carried out in a battery-grade glove box or a controlled dry room. A glove-box system for lithium-metal work generally includes an antechamber, gas purification, oxygen and moisture monitoring, circulation, and regeneration functions. The assembly area requires coin cell cases and covers, gaskets, spacers, and spring washers, separators and counter electrodes, electrolyte and a precision pipette or electrolyte filling device, insulated tweezers and solvent-resistant tools, a manual, pneumatic, or electric coin cell crimper, cleaning wipes, and a controlled waste container. The assembly sequence must be defined before the line is commissioned. An operator should be able to identify each component, confirm its orientation, add the correct electrolyte quantity, and place the stack in the crimping die without leaving the controlled atmosphere.

For laboratories assembling many cells, an automatic coin cell assembly platform can combine material loading, stacking, electrolyte filling, and case sealing. TOB's published TOB-ASCC-20 system is designed for 20 and 24 series coin cells and includes a visual inspection function for electrode alignment and coating quality. The company lists a reference speed of approximately 60 pieces per hour and notes that the machine can be operated in a glove box or dry room, subject to the final configuration and process requirements.

Testing and Data Collection The testing area normally includes a multi-channel coin cell battery tester for charge-discharge cycling, an electrochemical workstation for cyclic voltammetry and impedance measurements, an internal-resistance meter where required, temperature-controlled test equipment for temperature-dependent studies, a sample rack and software system for cell identification and test records, and reusable split test cells for specialised screening or in-situ research. Testing capacity should be selected together with assembly capacity. There is little benefit in assembling a large batch of cells if the tester cannot begin the test sequence promptly or if the laboratory cannot keep track of the cell history.

TOB New Energy Technology Co., Ltd.