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, including:

• 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 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/performance of materials and components.

Research Focus

To shed light on the research challenges, HIPERZAB will further focus on:

• Unraveling the correlations between materials, operating conditions, and electrochemical phenomena upon cycling
• Conducting operando characterisations and multiscale modelling

Sustainability Approach

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