CORE USE CASE

CORE USE CASE

Our NiCo Electrode in Alkaline Electrolyzers

A bi-metallic NiCo catalyst deposited on large-area Ni foam (100 to 1000 cm2) by electroless deposition. The same electrode works as both HER cathode and OER anode at 80 mV and 260 mV overpotential at 100 mA/cm2 in 30 wt% KOH (no IR correction).

Polarization (RT vs 60 °C)

TESTBED
Polarization · AEM Electrolyzer Testbed30 wt% KOH · commercial Zirfon separator1.41.51.61.71.81.92.02.10.000.250.500.751.00Current density (A/cm²)Cell potential (V)1.81 V1.62 VRoom temp · 81.8%60°C · 91.3%Baseline run with commercial Zirfon. IONZERA targets a lower membrane voltage drop.

Bifunctional, tested on both sides

The same electrode was operated as both cathode and anode in the 5 cm2 AEM test cell. HER overpotential is 80 mV and OER overpotential is 260 mV at 100 mA/cm2 in 30 wt% KOH, without any IR correction.

Industrial current density at modest voltage

With our bifunctional NiCo electrode on both sides and a commercial Zirfon separator (500 um), the AEM cell logs 0.5 A/cm2 at 1.81 V at room temperature (82% energy efficiency) and 1.62 V at 60 deg C (91.4%).

Large-area substrate

The electroless deposition process has been applied to Ni foam substrates from 100 to 1000 cm2. Bench-scale evaluation and pilot-scale stacks can both be supported from the same product line.

Validated long-term stability

The same bifunctional NiCo electrode paired with a commercial Zirfon separator was tested for 1000 continuous hours at 0.5 A/cm2 and 40 deg C in 30 wt% KOH. The cell voltage drifted by just 21 uV/hr.

Where the electrode sits in an alkaline electrolyzer

In an alkaline water electrolysis cell, two electrodes sit immersed in concentrated KOH electrolyte separated by a porous separator membrane. The cathode hosts the hydrogen evolution reaction (HER) and the anode hosts the oxygen evolution reaction (OER). The catalyst layer on each electrode determines the overpotential needed to drive each half-reaction at a given current density.

Our bifunctional NiCo electrode is a bi-metallic transition-metal catalyst deposited on large-area Ni foam (100 to 1000 cm2) by electroless deposition. The same coated electrode operates as both HER cathode and OER anode. Measured in 30 wt% KOH at 100 mA/cm2 without any IR correction, HER overpotential is 80 mV and OER overpotential is 260 mV.

Substrate: Ni foam, 100 to 1000 cm2 area
Active layer: bi-metallic NiCo, electroless-deposited
HER overpotential: 80 mV at 100 mA/cm2 (no IR correction)
OER overpotential: 260 mV at 100 mA/cm2 (no IR correction)
Bifunctional: same electrode used on cathode and anode
1.81 V (82%)

0.5 A/cm2 @ RT

1.62 V (91.4%)

0.5 A/cm2 @ 60 deg C

1.79 V

1.0 A/cm2 @ 60 deg C

Performance in a full AEM cell with our bifunctional NiCo electrode and commercial Zirfon separator

The bifunctional NiCo electrode was assembled on both sides of a 5 cm2 AEM cell with a commercial Zirfon separator (500 um) and 30 wt% KOH electrolyte in a zero-gap configuration. Under these conditions the cell reaches an industrial current density of 0.5 A/cm2 at 1.81 V at room temperature (82% energy efficiency) and 1.62 V at 60 deg C (91.4%).

At higher current density, the same bifunctional NiCo electrode and commercial Zirfon separator measured 2.05 V at 1.0 A/cm2 (room temperature) and 1.79 V at 1.0 A/cm2 (60 deg C). The 60 deg C polarization curve sits well below the room-temperature curve across the full current-density range.

1000-hour stability validated on our bifunctional NiCo electrode with commercial Zirfon

A continuous 1000-hour chronopotentiometry run was performed with our bifunctional NiCo electrode on both sides of a 5 cm2 AEM cell and a commercial Zirfon separator (500 um) at 0.5 A/cm2 and 40 deg C in 30 wt% KOH. The cell voltage drifted by just 21 uV/hr over the full window.

Linear-sweep polarization curves recorded before and after the 1000-hour run differ by only 30 mV at the 0.5 A/cm2 operating point. The bifunctional NiCo electrode and commercial Zirfon separator together held the operating envelope across the full duration.

  • Voltage degradation rate: 21 uV/hr
  • DeltaV before/after at 0.5 A/cm2: 30 mV
  • Conditions: 0.5 A/cm2, 40 deg C, 30 wt% KOH, AEM cell, zero-gap, commercial Zirfon separator
  • Same bifunctional NiCo electrode used on both sides throughout the run
1000-hour Stability · AEM Electrolyzer Testbed0.5 A/cm² · 40°C · 30 wt% KOH · commercial Zirfon1.701.751.801.851.9002004006008001000Time (hours)Cell potential (V)DEGRADATION0 µV/hrBefore vs after 1000 hr LSVBeforeAfterΔV = 30 mV @ 0.5 A/cm²Baseline run with commercial Zirfon. Ohmic budget shrinks further with IONZERA.

Renewable-coupled testing on the same bifunctional NiCo electrode

Solar irradiance data sampled sunrise to sunset was converted to a current-density schedule and applied to the AEM cell with our bifunctional NiCo electrode on both sides and a commercial Zirfon separator (500 um) for 9 continuous days. Cell voltage tracked the input profile and no major changes were observed after 9 cycles. Current density peaked near 570 mA/cm2 during the daily maxima.

Wind variation data over 100 hours was likewise converted to a current-density schedule and applied to the same AEM cell. Current density ranged from 0 to 0.78 A/cm2 with rapid gusts and sustained troughs. The linear-sweep polarization curve recorded before and after the 100-hour run differ by only 20 mV at the 0.5 A/cm2 operating point.

9 daysContinuous solar cycles
100 hoursWind dynamic-load run
20 mV @ 0.5 A/cm2DeltaV after wind cycling

PV-derived current profile

9 DAYS
9-Day Solar-Coupled OperationAEM testbed · 40°C · 30 wt% KOH · current density from PV irradiance0.570j (A/cm²)1.951.40V (cell)1.80 V0123456789Time (days)9 days · no driftPV irradiance → current-density schedule applied to AEM stack with commercial Zirfon.

Wind-derived current profile

100 HR
100-Hour Wind-Coupled OperationAEM testbed · 40°C · 30 wt% KOH · current density from wind variation0.780j (A/cm²)1.951.40V (cell)020406080100Time (hours)Before vs after 100 hrΔV = 20 mV @ 0.5 A/cm²Wind-data → current-density schedule applied to AEM stack with commercial Zirfon.

How to evaluate it on your own cell

Samples are available across the 100 to 1000 cm2 size range. A typical evaluation begins with a 5 cm2 coupon at the same conditions used in our published test cell (30 wt% KOH, zero-gap, AEM assembly, commercial Zirfon separator) so that your team can reproduce the bifunctional NiCo electrode performance directly. Larger sizes can be supplied for pilot stack integration once the bench-scale numbers are confirmed.

We also offer IONZERA, our own next-generation separator membrane, as a sibling product for stacks looking to upgrade the membrane side. The two products are sold independently. Both can be evaluated against the same operating conditions.

Frequently asked questions

Why use a bifunctional NiCo electrode for alkaline water electrolysis?

Our bifunctional NiCo electrode operates as both HER cathode and OER anode at 80 mV and 260 mV overpotential at 100 mA/cm² in 30 wt% KOH (no IR correction). For alkaline water electrolysis, using a single electrode SKU on both sides simplifies stack BOM and qualification.

What cell-level performance is published?

In a 5 cm² AEM cell with bifunctional NiCo electrode on both sides and a commercial Zirfon separator (500 µm) at zero-gap, the cell logs 0.5 A/cm² at 1.81 V at room temperature (82% efficiency) and 1.62 V at 60 °C (91.4%). At 1.0 A/cm²: 2.05 V at RT and 1.79 V at 60 °C.

What is the stability baseline?

Continuous 1000-hour chronopotentiometry at 0.5 A/cm² and 40 °C in 30 wt% KOH (bifunctional NiCo electrode on both sides, commercial Zirfon separator) showed voltage drift of 21 µV/hr. Before/after linear-sweep polarization curves differ by 30 mV at the operating point.

Is the electrode validated for renewable-coupled operation?

Yes. PV-irradiance-derived current schedules applied for 9 continuous days (peaks ~570 mA/cm²) and wind-variation-derived schedules for 100 hours (0 to 0.78 A/cm²) on the same cell. ΔV at 0.5 A/cm² before and after the 100-hour wind run: 20 mV.

What substrate sizes ship?

The bifunctional NiCo electrode is produced on Ni foam in the 100 to 1000 cm² size range. Bench-scale 5 cm² coupons matching the published test cell are also available so customers can reproduce numbers on their own rig before scaling up.

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