Anion Exchange Membrane Electrolysis for Renewable Hydrogen Production on a Wide-Scale

Project Information

ANIONE

Grant agreement ID: 875024

DOI

10.3030/875024

Project closed

EC signature date 9 December 2019

Start date 1 January 2020

End date 30 September 2023

Funded under

• SOCIETAL CHALLENGES - Secure, clean and efficient energy

Total cost

€ 1 999 995,00

EU contribution

€ 1 999 995,00

Coordinated by

CONSIGLIO NAZIONALE DELLE RICERCHE
Italy

Periodic Reporting for period 3 - ANIONE (Anion Exchange Membrane Electrolysis for Renewable Hydrogen Production on a Wide-Scale)

Reporting period: 2023-01-01 to 2023-09-30

Summary of the context and overall objectives of the project

The overall objective of the ANIONE project was to develop a high-performance, cost-effective and durable anion exchange membrane water electrolysis technology. The approach regarded the use of an anion exchange membrane (AEM) and ionomer dispersion in the catalytic layers for hydroxide ion conduction. This system combines the advantages of both proton exchange membrane and liquid electrolyte alkaline technologies allowing the scalable production of low-cost hydrogen from renewable sources. The focus was on developing hydrocarbon AEM membranes consisting of either poly(arylene) or poly(olefin) backbone with quaternary ammonium hydroxide groups carried on tethers anchored on the polymeric backbone. Advanced short side chain Aquivion-based anion exchange polymer membranes comprising a perfluorinated backbone and pendant chains, covalently bonded to the perfluorinated backbone, with quaternary ammonium groups are developed in parallel. The goal was to achieve for the AEM membranes conductivity and stability comparable to their protonic analogous and novel nanofiber reinforcements for improved mechanical stability and reduced gas crossover. The project validated a 2 kW AEM electrolyser with a hydrogen production rate of about 0.4 Nm3/h (TRL 4) as proof-of-concept of the new technology.
Innovative anion exchange membranes were developed in conjunction with non-critical raw materials (CRMs)-based high surface area electrocatalysts and membrane-electrode assemblies also based on CRM-free components. Cost-effective stack hardware materials and novel stack designs contribute to decrease the capital costs of these systems. After appropriate screening of active materials, in terms of performance and stability, in single cells, these components were validated in a pressurised AEM electrolysis stack and assessed in terms of performance, load range and durability under steady-state and dynamic operating conditions. The developed solutions were expected to contribute significantly to reducing the electrolyser CAPEX and OPEX costs. The project has delivered a techno-economic analysis and an exploitation plan for successive developments with the aim to bring the innovations to market. The aim is to contribute to the roadmap addressing the achievement of a wide scale decentralised hydrogen production infrastructure with the long-term goal to reach net zero CO2 emissions in EU by 2050.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

The work has addressed AEMWE technology development. The main results are summarised in the following. Protocols and procedures for AEM electrolysis assessment have been defined to assess the achievements of the project milestones.
Fluorinated and hydrocarbon AEM ionomers with quaternary ammonium functional groups have been developed and characterized in terms of ion exchange capacity and anion conductivity. Composite membranes including different types of reinforcements and radical scavengers have been developed. Composite membranes have shown enhanced mechanical behaviour and OH- conductivity at 50 °C of 90-105 mS/cm.
Nanosized NiFe oxide, oxygen evolution, anode electrocatalyst and carbon supported Ni-based, hydrogen evolution, cathode electrocatalyst for AEM water electrolysis have been developed. These were characterised by a crystallite size in the range of 5-10 nm, low overpotential and high electrochemical stability.
Membrane-electrode assemblies based on catalyst-coated electrodes including nanosised Ni-based anode and cathode electrocatalysts have shown electrolysis performance of about 1.8 V at 1 A cm-2 and 50 °C. Stable performance has been observed during 2000 hrs steady state and 1000 hrs cycled (0.2 -1 A cm-2) operations. Large area (>100 cm2) MEAs are integrated in a simplified stack design.
The novel solutions developed in the project have been validated in an anion exchange membrane electrolysis stack of 2 kW capacity with a hydrogen production rate of about 0.4 Nm3/h (TRL 4) showing 57 kWh/kg H2 energy consumption at 1 A cm-2. A second stack was assembled and showed improved durability with continuous increase of performance with time.
Dissemination of project results have been mainly carried out through the project website and presentations at conferences and workshops.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The achieved objectives comply with the general aim of the ANIONE project to improve Anion Exchange Membrane water electrolysis in order to favour green hydrogen production from renewables on a wide-scale. The results achieved are promising especially in terms of operating current density (1 A cm-2), low energy consumption (57 kWh/kg H2 at 1 A cm-2) showing good perspectives to reduce the performance gap with respect to PEM electrolysis while using cheaper and widely available stack materials and components.
Novel electrocatalysts for oxygen and hydrogen evolution reactions have been developed showing enhanced performance and stability compared to the state of the art. Similar results have been observed for the reinforced hydrocarbon membrane developed in the project showing conductivity values above 100 mS cm-1 that are larger than those achievable with benchmark AEM membranes (50 mS cm-1).
A single cell performance of 1 A cm-2 at about 1.8 V/cell has been achieved using non-critical raw materials and hydrocarbon membranes. This is not far from the performance typically obtained with Nafion-based PEM electrolysers using precious metals and at least 2-times better than conventional alkaline electrolysis. No voltage degradation rate has been recorded during the first 2000 h operation (negative variation of cell voltage vs. time) compared to a voltage decay rate of about 5 µV/h typically observed for PEM systems. A low gas cross over (0.2%) has been recorded at ambient pressure. This is lower than what is typically observed with perfluorinated membranes.
The project has validated this new technology in a 2 kW AEM electrolyser with a hydrogen production rate of about 0.4 Nm3/h (TRL 4) and an energy consumption lower than 57 kWh/kg H2 at 1 A cm-2 current density. Stable performance was achieved. Another relevant goal regarded the achievement of a perspective reduction of capital costs, in large scale production, less than 0.86 M€ / (t/d H2).
The potential impacts are essentially dealing with:
- Stable and cost-effective components for AEM water electrolysers that will reduce substantially the risk to incur in supply bottlenecks;
-New knowledge with respect to the design and operation of an AEM electrolyser stack including the new components;
-Increased competitiveness in production of green hydrogen at low cost from renewable sources.
ANIONE project also contributes to several environmental and socially important impacts such as renewable hydrogen production, energy savings and energy security in Europe, low-cost electrolysis and potential creation of new jobs in distributed hydrogen production. The diffusion of AEM electrolysis technology can especially contribute in providing specific environmental benefits.

ANIONE POLARISATION CURVES

ANIONE Large area membrane and electrodes for stack assembling

Comparison of AEMEL ANIONE and PEMEL Polarisation curves at CNR-ITAE

ANIONE LOGO

ANIONE STACK

ANIONE DURABILITY TEST

ANIONE SINGLE CELL TESTING