Non-Reversible galvanic cell based on aluminum

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Renewable resources can generate electricity and heat with short-term storage options available, but long-term storage solutions are lacking. Aluminium-based energy systems offer a solution with high energy density and the potential to store energy over longer periods. Aluminium-water reactions can produce hydrogen and heat to provide energy. An exploratory project aims to develop an aluminium-air fuel cell to increase the share of electricity that can be produced from aluminium reactions. 1. Project idea descriptionIntroductionToday, electricity and heat can be produced cheaply based on renewable resources like solar, wind or hydropower, and the short term or diurnal storage of energy is available with market-proven products such as thermal storage, pumped hydro and batteries (secondary electrochemical cells). However, solutions for storing energy over longer time periods such as months or seasons are scarce or lacking multiplication potential, which is a significant problem for the resilience of our energy systems at peak season, i.e., in winter. Aluminium based energy systems offer this opportunity. With a high energy density of 23.5 MWh/m3, and being the third most common metal in the earth’s crust, it is readily available and cheap to store. With inert anode processes such as the one developed by Elysis, aluminium can now also be produced without greenhouse gas emissions. The SPF has so far developed technologies for providing energy from aluminium that are based on aluminium-water reactions that produce hydrogen and heat. With these technologies, it is possible to provide 23.5 MWh energy per m3 of solid aluminium, of which 25% in the form of electricity and 75% as heat.Within this new explorative project we would like to increase the share of electricity that can be produced from the energy released by aluminium reactions, by developing an aluminium air (AlAir) fuel cell, i.e. a tertiary electrochemical cell that produces electricity based on the oxidation of aluminium and is recharged by replacement of the aluminium anode.What problem would you like to solve? We would like to solve the problem of seasonal energy storage developing based on aluminium as an energy carrier that is used in an Al-air fuel cell to produce electricity and heat. The challenges of the Al-air electrochemical cells are a) the handling of hydrogen and heat as inevitable by-products of the cell operation, b) the replacement of the aluminium anode (fuel) and c) the regeneration of the electrolyte. A by-product of AlAir batteries, due to the reaction of aluminium with oxygen, is precipitated aluminium hydroxide in the electrolyte. Since the precipitation reduces the cells efficiency, the electrolyte has to be purified.Who are the customers and how will they profit from a solution?Customers will profit from an Eco-friendly winter peak energy unit that provides electricity and heat based on an energy carrier that has an extremely high energy density (about 50 – 100 times higher than Li-ion batteries). Whether they are private households or companies, the AlAir fuel cell will deliver a reliable energy solution based on renewable energy stored in aluminium, that can deliver electricity and heat anytime and anywhere.Customers are private households and industry with high winter energy demand. They will profit from an eco-friendly winter peak energy unit or backup energy unit Unlike currently available combined heat and power units that are based on fossil fuels, our new technology will provide heat and electricity based on renewable energy only, and with a much higher energy density than Li-ion batteries (10-20 times higher). The AlAir fuel cell will deliver clean electricity and heat anytime and anywhere.How does your project idea affect energy savings of CO2 emissions?The development of an efficient AlAir fuel cell will help to overcome winter energy gaps that are currently covered by fossil fuels and for which no renewable technology has penetrated the market yet. Excess energy during summer, when renewables, in particular solar energy, are abundant, can be used to produce aluminium from aluminium oxide or hydroxide, based on the CO2-free inert electrode process developed e.g., by Elysis or Arctus Metals. Once energy becomes scarce in winter, aluminium anodes are used in the electrochemical cell to produce electricity and heat, with the only by-products being hydrogen and Al(OH)3.Additionally, AlAir fuel cells can further be used in various applications such as emergency power backup, portable devices, or e-mobility.2. Current Status and previous activitiesSPF already masters the conversion of aluminium with water to heat, H2 and Al(OH)3, with an overall electrical efficiency of 25%. The goal of the Al-air tertiary cell is to increase the electrical efficiency to 35% in a first step, und to higher values later on. First experiments in a student research project with currently available materials showed the principal feasibility of an aluminium-air cell and stable operation over 10 hours. However, with an electrical efficiency of 20%, the technology is not yet where it has to be in order to be of advantage compared to competing technologies.3. Resources neededA current project is funded with CHF 15’000 by a private foundation, with additional resources from OST regarding student projects. This allowed us to show the feasibility in the lab and test a limited set of electrolytes and air breathing cathodes. From there on, SPF would like to tackle the next steps as described in WP1-3 in order to achieve longer runtimes.Planned work packages are:WP1: Test different combinations of electrolyte – electrode combinations. Different air breathing cathodes are combined with different electrolyte compositions in order to increase operation voltage and power as well as time of stable operation (increase of efficiency and lifetime)WP2: In a second step, larger amounts of aluminium will be used for the anode and longer operation will be tested. This will lead to precipitation of Al(II) salts from the electrolyte WP3: A method for purification / filtering of the electrolyte will be designed and tested with the aim to increase time of stable operation.The Energy Lab can help with funding on the one hand, and by the large community of knowledge and expertise that can provide useful inputs and discussions as well as contacts to other experts or industry.

Project Idea Metadata

Project Idea Name: Non-Reversible galvanic cell based on aluminum
Date: 2/13/2023 1:50:31 PM
Administrators:

Project Idea Description

1. Project idea description

Introduction

Today, electricity and heat can be produced cheaply based on renewable resources like solar, wind or hydropower, and the short term or diurnal storage of energy is available with market-proven products such as thermal storage, pumped hydro and batteries (secondary electrochemical cells). However, solutions for storing energy over longer time periods such as months or seasons are scarce or lacking multiplication potential, which is a significant problem for the resilience of our energy systems at peak season, i.e., in winter.

Aluminium based energy systems offer this opportunity. With a high energy density of 23.5 MWh/m³, and being the third most common metal in the earth’s crust, it is readily available and cheap to store. With inert anode processes such as the one developed by Elysis, aluminium can now also be produced without greenhouse gas emissions. The SPF has so far developed technologies for providing energy from aluminium that are based on aluminium-water reactions that produce hydrogen and heat. With these technologies, it is possible to provide 23.5 MWh energy per m3 of solid aluminium, of which 25% in the form of electricity and 75% as heat.

Within this new explorative project we would like to increase the share of electricity that can be produced from the energy released by aluminium reactions, by developing an aluminium air (AlAir) fuel cell, i.e. a tertiary electrochemical cell that produces electricity based on the oxidation of aluminium and is recharged by replacement of the aluminium anode.

What problem would you like to solve?

We would like to solve the problem of seasonal energy storage developing based on aluminium as an energy carrier that is used in an Al-air fuel cell to produce electricity and heat. The challenges of the Al-air electrochemical cells are a) the handling of hydrogen and heat as inevitable by-products of the cell operation, b) the replacement of the aluminium anode (fuel) and c) the regeneration of the electrolyte. A by-product of AlAir batteries, due to the reaction of aluminium with oxygen, is precipitated aluminium hydroxide in the electrolyte. Since the precipitation reduces the cells efficiency, the electrolyte has to be purified.

Who are the customers and how will they profit from a solution?

Customers will profit from an Eco-friendly winter peak energy unit that provides electricity and heat based on an energy carrier that has an extremely high energy density (about 50 – 100 times higher than Li-ion batteries). Whether they are private households or companies, the AlAir fuel cell will deliver a reliable energy solution based on renewable energy stored in aluminium, that can deliver electricity and heat anytime and anywhere.

Customers are private households and industry with high winter energy demand. They will profit from an eco-friendly winter peak energy unit or backup energy unit Unlike currently available combined heat and power units that are based on fossil fuels, our new technology will provide heat and electricity based on renewable energy only, and with a much higher energy density than Li-ion batteries (10-20 times higher). The AlAir fuel cell will deliver clean electricity and heat anytime and anywhere.

How does your project idea affect energy savings of CO2 emissions?

The development of an efficient AlAir fuel cell will help to overcome winter energy gaps that are currently covered by fossil fuels and for which no renewable technology has penetrated the market yet. Excess energy during summer, when renewables, in particular solar energy, are abundant, can be used to produce aluminium from aluminium oxide or hydroxide, based on the CO2-free inert electrode process developed e.g., by Elysis or Arctus Metals. Once energy becomes scarce in winter, aluminium anodes are used in the electrochemical cell to produce electricity and heat, with the only by-products being hydrogen and Al(OH)₃.

Additionally, AlAir fuel cells can further be used in various applications such as emergency power backup, portable devices, or e-mobility.

2. Current Status and previous activities

SPF already masters the conversion of aluminium with water to heat, H₂ and Al(OH)₃, with an overall electrical efficiency of 25%. The goal of the Al-air tertiary cell is to increase the electrical efficiency to 35% in a first step, und to higher values later on. First experiments in a student research project with currently available materials showed the principal feasibility of an aluminium-air cell and stable operation over 10 hours. However, with an electrical efficiency of 20%, the technology is not yet where it has to be in order to be of advantage compared to competing technologies.

3. Resources needed

A current project is funded with CHF 15’000 by a private foundation, with additional resources from OST regarding student projects. This allowed us to show the feasibility in the lab and test a limited set of electrolytes and air breathing cathodes. From there on, SPF would like to tackle the next steps as described in WP1-3 in order to achieve longer runtimes.

Planned work packages are:

WP1: Test different combinations of electrolyte – electrode combinations. Different air breathing cathodes are combined with different electrolyte compositions in order to increase operation voltage and power as well as time of stable operation (increase of efficiency and lifetime)

WP2: In a second step, larger amounts of aluminium will be used for the anode and longer operation will be tested. This will lead to precipitation of Al(II) salts from the electrolyte

WP3: A method for purification / filtering of the electrolyte will be designed and tested with the aim to increase time of stable operation.

The Energy Lab can help with funding on the one hand, and by the large community of knowledge and expertise that can provide useful inputs and discussions as well as contacts to other experts or industry.