Coin cells remain one of the most useful test platforms in battery research. They use relatively small quantities of active material, can be assembled in a controlled laboratory environment, and allow researchers to compare electrode formulations and electrochemical performance before moving to larger cell formats.

For a research team, however, setting up a coin cell line is more involved than purchasing a crimping machine and a glove box. The quality of the final test cell is determined by the entire chain: material preparation, slurry mixing, coating, drying, calendering, disc cutting, final drying, assembly, electrolyte filling, sealing and testing. A problem introduced at one station may only become visible several days later in the cycling data.

Xiamen TOB New Energy Technology Co., Ltd. (TOB NEW ENERGY) provides laboratory equipment, battery materials and integrated solutions for lithium-ion, sodium-ion and other battery research applications. The following guide outlines how to plan a coin cell laboratory line around the actual research workflow.

Where a coin cell laboratory line fits in battery R&D
A coin cell line is usually positioned between material development and larger-scale cell production. It is particularly useful when a laboratory needs to:
• screen new cathode and anode materials;
• compare binders, conductive additives, solvents and electrode formulations;
• evaluate coating loading, drying conditions and calendering density;
• study separators, electrolytes and electrode surface treatments;
• build lithium-metal half-cells or full cells for early electrochemical testing;
• investigate lithium-ion and sodium-ion chemistries with limited material quantities;
• generate repeatable data before investing in pouch, cylindrical or prismatic cell equipment;
• train operators and validate a process before transferring it to a pilot line.

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

The line is best understood as a controlled screening platform rather than a small version of a mass-production line. Its purpose is to produce enough consistent cells to answer a research question. That means repeatability, traceability and clean handling are usually more important than maximum output.

Equipment required from electrode preparation to testing
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.

1. Material preparation and drying
The basic equipment normally includes:
• a precision balance for accurate formulation weighing;
• a vacuum drying oven for active materials, conductive agents, binders, electrodes and separators;
• storage containers and trays suitable for dry or inert-atmosphere handling;
• a moisture meter or other material inspection equipment where required by the chemistry;
• solvent-resistant tools, transfer vessels and labels for batch traceability.
Material drying should be planned around the material rather than around 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.

2. 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;
• a particle-size or dispersion inspection method;
• a clean workbench for formulation preparation.
Cathode and anode slurries do not necessarily follow the same mixing sequence. A conventional cathode process may combine the active material and conductive agent before adding the binder. A conventional aqueous anode process may prepare the CMC solution first, then mix graphite and conductive additives before adding SBR. The equipment should allow the laboratory to reproduce the selected sequence without introducing air or contamination.

3. Coating and electrode drying
The electrode preparation section normally includes:
• a laboratory blade coater or film applicator;
• a heated coating bed, preferably with vacuum hold-down;
• interchangeable doctor blades or coating heads;
• a vacuum drying oven or controlled drying chamber;
• 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. The important selection criteria are not simply coating width and speed. Blade parallelism, coating-gap adjustment, substrate flatness, drying uniformity and data recording have a direct effect on areal loading.

4. 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;
• trays for sorting good discs from discs with burrs, cracks or coating defects.
The cutting die must remain sharp and aligned. A burr that appears insignificant during preparation can damage the separator during assembly and create a micro-short during cycling. For this reason, disc inspection is a process-control step, not merely a visual clean-up operation.

5. 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.

6. 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;
• 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.

Process flow and the relationship between materials and parameters
A coin cell process should be written as a recipe with a permitted operating window, not as a single number that is assumed to work for every material system.

Material preparation
The cathode and anode systems should be separated from the beginning. Typical lithium-ion laboratory work may use an NMP-based PVDF cathode slurry and a water-based CMC/SBR anode slurry. Cathodes are commonly coated on aluminum foil, while anodes are commonly coated on copper foil. A lithium-metal half-cell uses lithium metal as the counter electrode; a sodium-ion programme requires a compatible sodium-based counter-electrode arrangement.

The drying temperature and time should follow the material and binder system. TOB's published coin cell laboratory process information gives representative examples such as baking conductive agent at 120 °C for eight hours and PVDF powder at 80 °C for eight hours. These figures are starting points for the stated process, not universal specifications for every powder or binder.

Slurry mixing
Mixing order, vacuum level, rotation speed, temperature and hold time should be recorded for every batch. TOB's published process notes identify representative control targets for anode slurry such as viscosity of approximately 2,000–4,000 mPa·s, particle size below about 35 μm and solids content in the range of 40–70%. The usable range still depends on the active material, conductive additive, binder, solvent and coating method.

For an aqueous anode route, the published process guidance also specifies deionised water with conductivity at or below 1 μS/cm, workshop temperature below 40 °C and humidity at or below 25% RH. If a laboratory uses a different chemistry, its own process-development plan should replace these values.

Coating and calendering
Coating parameters should be matched to the target areal capacity and electrode loading. TOB's published process information gives a representative positive-electrode coating density of 20–40 mg/cm² per side. The correct value depends on active material capacity, formulation, foil type, electrode balance and the intended test protocol.

After coating, the electrode should be dried until residual solvent and moisture are within the laboratory's defined limits. Calendering then adjusts the electrode thickness and density. Too little compaction may leave poor contact and excessive void volume; too much compaction can restrict electrolyte wetting and ion transport. The best setting is therefore a material-specific window rather than a fixed pressure copied from another project.

Cutting, final drying and assembly
The electrode and separator should be checked for burrs, cracks, coating drop-out and contamination before entering the final drying step. TOB's published laboratory process describes a representative final drying condition of 120 °C for six hours under vacuum. The actual condition should be confirmed against the separator, binder, electrode chemistry and the laboratory's moisture target.

Inside the glove box, the operator should follow a fixed stacking order and use a written checklist. Electrolyte volume should be controlled with a calibrated pipette or filling device. Crimping force must be matched to the cell format, gasket material, stack height and die design. A published TOB reference describes a typical CR2032 crimping-force range of approximately 500–800 kg for polypropylene gaskets, but the final setting should be established by validation tests rather than transferred blindly between machines.

Testing
Every cell should carry an identification code linked to its material batch, coating batch, operator, assembly date, crimping setting and test programme. This information becomes especially important when a cell shows low open-circuit voltage, abnormal self-discharge, leakage or unusually high impedance.

Laboratory layout and safety requirements
The layout should follow the direction of material movement and should prevent wet, dusty or solvent-heavy work from interfering with the dry assembly area.

A practical arrangement is:
1. Material preparation area — weighing, sieving and initial storage.
2. Mixing area — slurry preparation, filtration and viscosity checks.
3. Coating and drying area — coating, oven operation and electrode inspection.
4. Calendering and cutting area — roller pressing, disc punching and sorting.
5. Dry storage and transfer area — vacuum-dried electrodes and separators held in sealed containers.
6. Glove-box or dry-room area — electrolyte handling, stacking and crimping.
7. Testing area — battery testers, electrochemical workstations and sample records.
The line should also provide suitable electrical capacity, vacuum, compressed air, inert gas, exhaust and solvent-handling arrangements. Oven placement should account for heat output and access for maintenance. The glove box should be positioned so that the antechamber can be loaded without blocking the main walkway.

Safety planning must cover more than the machines themselves. Lithium metal, electrolyte solvents, NMP, conductive powders and heated ovens each require their own handling and storage controls. The laboratory should provide appropriate ventilation, PPE, spill-response materials, labelled waste containers, fire protection, emergency power isolation and access to current safety data sheets. Personnel should be trained in glove-box operation, electrolyte handling, lithium-metal handling, press operation and battery testing before independent work begins.

The final design must follow local fire, electrical, chemical and occupational-safety requirements. Equipment specifications alone do not constitute a complete safety assessment.

Configuration suggestions: from one machine to a small laboratory line
The right configuration depends on the research question, weekly cell demand and the level of process repeatability required.
Configuration A: First-cell or teaching laboratory
A basic setup can begin with:
• a precision balance;
• a small vacuum mixer;
• a manual blade coater;
• a vacuum drying oven;
• a manual electrode disc cutter;
• a compact glove box;
• a manual coin cell crimper;
• a small multi-channel battery tester.
This configuration is suitable for occasional material screening, student training and early feasibility work. It keeps the investment focused, but it also leaves more steps dependent on operator technique. A written operating procedure and a simple batch-record form are essential.

Configuration B: Repeatable research workstation
For a laboratory producing cells every week, the configuration should normally add:
• a higher-control vacuum planetary mixer;
• a heated laboratory coater with adjustable blade gap;
• a laboratory roller press;
• a precision disc cutter with replaceable dies;
• a dedicated vacuum drying oven for electrodes and separators;
• a pneumatic or electric crimping machine;
• a larger glove box with oxygen and moisture monitoring;
• a multi-channel tester with traceable data management.
This is often the most balanced arrangement for universities, corporate R&D departments and start-ups. It improves repeatability without adding the complexity of a fully automated line.

Configuration C: Small integrated coin cell line
A small integrated line is appropriate when a team is screening many formulations, needs a consistent output for statistical comparison or wants to prepare for pilot-scale development. It may include:
• separate material and electrode drying capacity;
• a controlled vacuum mixer and slurry inspection tools;
• a laboratory coater with process recording;
• a roller press, disc cutter and separator cutter;
• a glove box or dry-room assembly zone;
• an automatic coin cell assembly system or electric crimper with controlled electrolyte filling;
• enough battery-test channels for the planned sample volume;
• central batch tracking and operator training.

TOB NEW ENERGY supplies coin cell laboratory equipment as individual machines or as a configured laboratory line. The company's published TOB-CCL01 solution covers coin cell laboratory equipment and materials for lithium-ion battery R&D, with the final equipment combination adapted to the customer's chemistry, cell format, throughput and laboratory conditions.

The most reliable way to specify a line is to begin with the intended experiment, then work backward through material quantities, electrode loading, number of cells per condition, assembly environment and testing schedule. When each station is designed around the next one, the laboratory gains more than a collection of machines: it gains a repeatable path from material powder to defensible electrochemical data.

About TOB NEW ENERGY
Xiamen TOB New Energy Technology Co., Ltd. provides battery materials, laboratory equipment, pilot-line equipment and production-line solutions. Its published product range covers slurry mixing, coating, drying, roller pressing, electrode cutting, coin cell electrolyte filling, crimping, glove-box operation and battery testing.

For coin cell laboratory line planning, customers can contact TOB NEW ENERGY for equipment selection, process matching, laboratory layout, installation, commissioning and operator training.

Contact
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Website: www.tobmachine.com