High performing electrically rechargeable zinc-air batteries for sustainable mid-term energy storage

Introduction

Energy storage is critical for the EU energy system to reach a large renewable energy share, climate neutrality, and affordable energy costs. Currently available energy storage solutions suffer from limited storage time, the use of toxic/flammable components, large amounts of critical raw materials (CRMs), and high costs that limit their large market deployment.

Advantages of Metal-Air Batteries

Metal-air batteries present several advantages such as:

• Cheap and abundant active materials (e.g., zinc + air)
• High gravimetric energy density
• Long-term stability

However, even in their more mature configuration, they cannot guarantee storage times greater than 4-12 hours. Additionally, the present mechanical recharging concepts drastically increase operation and maintenance costs.

Project Overview

HIPERZAB will design and validate at lab scale, for the first time ever, an Electrically Rechargeable Zinc-Air Battery (ERZAB) to enable breakthroughs in:

1. Cyclability
2. Storage time
3. Costs
4. Life cycle design

This battery is ideal for mid-term storage (days/weeks) to be coupled with renewables and electrolysers.

Innovative Components

To reach this goal, HIPERZAB will develop three innovative components:

1. A 3D porous Zn/biopolymer composite anode
2. An eco-friendly bilayer gel electrolyte based on naturally occurring precursors
3. A CRM-free cathode based on high entropy oxides (HEOs)

These components will be integrated into a single device proposing a radically new battery design that enables water/air management control during cycling and enhances the durability and performance of materials and components.

Research Challenges

To shed light on the research challenges, HIPERZAB will further focus on unraveling the correlations between materials, operating conditions, and electrochemical phenomena upon cycling through:

• Operando characterisations
• Multiscale modelling

Sustainability Focus

HIPERZAB's developments will be continuously guided by life cycle and circular economy approaches to ensure sustainable end-of-life options.