Energy storage is vital for the successful decarbonisation of the energy systems, balancing the generation and demand of renewable resources. However, current energy storage systems present limited lifespan, cost, energy and power density, and dynamic response features. As a solution to this issue, smart hybridization schemes coupling two different battery technologies into a single device aim to increase competitiveness of electrical energy storage by balancing power needs with energy needs. In particular, HYBRIS project (Grant Agreement No 963652) aims to develop a new hybrid energy storage system integrating Lithium Titanate (LTO) batteries, which enables high electricity output in periods of high-power demand, and Aqueous Organic Redox Flow (AORFB), high energy density components, making possible a long period of electricity supply between charging periods. Nevertheless, in order to achieve a resilient, affordable and sustainable energy transition, align with an increasingly stricter regulatory context, as per the new proposal regulation concerning battery and battery wastes, COM(2020) 798 final, it is mandatory to optimise environmental, economic and social dimensions at each life cycle of product development. Aiming at this objective, HYBRIS has successfully addressed a preliminary assessment of system’s sustainability, recyclability, and materials safety through a detailed snapshot of current battery partners’ technologies and a thorough review of the state-of-the-art (Deliverable 1.5) to activate an eco-design strategy fostering further design steps in a superior sustainability framework.
The eco-design study was initiated from a Life cycle assessment (LCA) applied to LTO and AORFB battery technologies. LCA is a structured, comprehensive, and internationally standardised method which has served to identify the environmental burdens associated with both technologies through their whole life cycle. Then, a screening of the materials safety, and a recyclability analysis complemented the LCA. Additional materials and literature studies were used to complete these analyses, specifically on nanosafety and nanotoxicity issues. With all this information, the eco-design proposal was built.
It is essential to mention that the proposed measures have different deployment terms (short, medium and long), according to specific R&D needs. The recommendations were grouped into five strategies:
- Reduction of the environmental impacts of the materials used to produce the battery. In turn, measures are divided into reducing the number of materials used in the batteries and selecting materials with a lower environmental footprint. This study includes numerous recommendations to be followed, e.g.: use of an LFP-LTO battery with lower environmental impacts, as well as use of recycled copper and aluminium for the metallic parts of the cell container; utilisation of a redox flow battery applying the aqueous organic electrolytes instead of alternatives such as vanadium-based electrolytes; and minimisation on the use of critical raw materials by optimised designs boosting their recycling.
- Decrease of the energy and water use. In this strategy, the study proposes two measures: using the best available techniques for the manufacturing process and increasing the renewables content in the electricity consumed.
- Minimisation of the use of hazardous substances. In this sense, the LFP-LTO battery contains less hazardous substances and a lower proportion than the NCO-LTO battery. Furthermore, the AORFB battery is the best alternative for hazardous substances content among redox flow batteries.
- Enhancement of the operating life. Two measures are presented to design for durability and repairability and design for ease of maintenance.
- Recyclability improvement of the batteries. In this study, designing for recycling is highly recommended. Additionally, direct recycling routes, with a better environmental footprint, are also recommended.
In order to summarise and visualise the provided results, the following spider chart establishes the effect of implementing the above-mentioned measures on the HYBRIS system.
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Written by Lomartov