The route from received electrodes to a test cell and its first measurement, on one page. Values such as clamping torque and the measurement sequence are in the electrode operation note; this chapter covers the order of work and the decisions people most often get wrong.
- LayoutAnode below · cathode above
- Pre-treatment · activationNone
- Clamping valuesDepend on your hardware
First timeLook at the sequence table in the first section, then follow the link on each row for the values. Read the gasket section before you assemble.
Done this beforeGo back to the gasket section. Most leaks and performance problems start there.
On this pageThe sequence at a glance
The sequence at a glance
| Step | What to do | Details |
|---|---|---|
| 1. Inspect | Check for creases, tears, catalyst delamination and crushed edges. Do not build a cell with a damaged sheet | Receiving · inspection |
| 2. Cut | If needed, cut to your active area: on a flat backing, in one pass, then clear the dust | Formats · made to order |
| 3. Stack up | Anode at the bottom, cathode on top; the electrolyte circulates on the anode side. Insulate the end plates with a PTFE sheet | Note · cell assembly |
| 4. Gaskets | Settle the thickness by clamping trials. See the next section | This chapter · gaskets |
| 5. Clamp | Tighten to the assembly guide for your cell hardware. Do not carry stack clamping conditions over to a cell | Note · cell assembly |
| 6. Electrolyte and heat-up | Circulate 0.1 M KOH and bring it to 50 °C. Confirm the temperature actually reached, not the setpoint | Note · operating conditions |
| 7. Start up | There is no separate activation step. Bring it to rated current and start measuring once the voltage has settled | Note · start-up |
| 8. Measure | Follow the measurement sequence, and match the conditions before comparing with the datasheet | Checking performance and reading data |
Gaskets: the most common failure
When a cell leaks or underperforms, the gasket is more often the cause than the electrode. Hold to two things.
- Seating
- O-rings ride out of their seat and the MEA gasket shrinks inwards. Push them back into place after seating.
- Thickness
- Do not simply match it to the electrode thickness. A nickel-foam anode compresses a great deal when clamped, by an amount that depends on the material. Try a few thicknesses, clamp each, and settle on one by checking for leaks and for cell performance.
What you do not need to do
- Pre-treatment. Electrodes ship cleaned and dried.
- Activation. There is no separate activation step; bring the cell to temperature and run at rated current.
- Orientation. Both faces are identical, so either side can face the membrane.
What this chapter is based on
- HXP-an datasheetPDF · 4.6 MB
- HXP-ca datasheetPDF · 908 KB
- Electrode operation noteWeb
Ask the engineer who built it
If your case is not covered here, send us the operating condition and what you observed. The engineer who designed the system answers directly.