self-assembled/healable Hybrid inorganic/Organic Polymer Electrolytes for sustainable electrochemical energy Storage

Project Information

HOPES

Grant agreement ID: 101026846

DOI

10.3030/101026846

Project terminated on 31 January 2024

EC signature date 23 March 2021

Start date 21 March 2022

End date 20 March 2024

Funded under

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Total cost

€ 196 707,84

EU contribution

€ 196 707,84

Coordinated by

CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS
France

Periodic Reporting for period 1 - HOPES (self-assembled/healable Hybrid inorganic/Organic Polymer Electrolytes for sustainable electrochemical energy Storage)

Reporting period: 2022-03-21 to 2024-03-20

Summary of the context and overall objectives of the project

In the field of electrochemical energy storage, researchers are actively pursuing safer and higher energy density alternatives to traditional Lithium-ion batteries (LiBs). The imperative to facilitate electric mobility and contribute to UN Sustainable Development Goal #7 drives this quest. All-solid-state batteries (ASSBs) have emerged as a focal point of research interest over the past decade. However, challenges persist in realizing the market introduction of this transformative energy storage technology.
However, challenges persist in realizing the market introduction of this transformative energy storage technology. Key among these challenges is the fabrication of inorganic, organic, or hybrid (inorganic/organic) solid-state electrolytes (SSEs) characterized by broad electrochemical stability windows (ESWs), high ionic conductivity values, and chemical resistance to alkali metals (e.g. Li°).
Solid Inorganic Electrolytes (SIEs): These demonstrate high ionic conductivity and extended ESW but face challenges related to thermal processing and scalability. Salt-in-Polymer Solid Polymer Electrolytes (SiP-SPEs): Easier to synthesize, but they exhibit lower ionic conductivity and a narrower stability window. Single-Ion SPEs (SISPEs): Promising cation transference numbers but limited overall conductivity. Solid Composite Electrolytes (SCEs): These combine active and passive fillers, aiming to merge desirable features.
The MSCA-IF project titled “Self-assembled/Healable Hybrid Inorganic/Organic Polymer Electrolyte for Electrochemical Energy Storage” (HOPES) aligns with EU initiatives. It targets high-performance, sustainable all-solid-state lithium metal batteries (LMBs). HOPES aims to overcome scientific and technological obstacles hindering the realization of ultra-performing ASSBs. Specific objectives include developing robust, self-healable, and recyclable SSEs through colloidal self-assembly of nanosized building blocks (known as Hairy NPs or HNPs). Additionally, the project seeks to establish structure-property correlations using advanced characterization techniques at various levels, including synchrotron-based characterizations. This ambitious initiative holds the promise of advancing the frontiers of solid-state battery technology, ensuring safety, high performance, and sustainability.

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

In the H2020-MSCA project "HOPES," our research journey commenced with a primary focus on exploring the electrochemical stability window (ESW) of poly(propylene glycol) (PPG)-based solid polymer electrolytes (SiP-SPEs). This investigation involved the application of Diels-Alder (DA) chemistry, specifically the coupling of hemitelechelic PPG-based prepolymers with maleimide, furan, and anthracene reactive end-groups, resulting in a mini-library of A-b-B-b-A macromolecular architectures with precisely defined DA adducts as the B junction unit connecting the PPG sub-blocks.
These meticulously designed model systems served as the foundation for a comprehensive case study. The initial phase involved a side-by-side comparison of the electrochemical stability windows (ESWs) of the prepolymers versus ABA triblock architectures. This comparison was facilitated through the analysis of linear sweep voltammetry (LSV) results. The evaluation then extended to consider the overall vs. Li+ conductivity values achieved by these SiP-SPEs, incorporating analyses of conductivity and lithium transference number (LTN) measurements.
Throughout the course of this project, our focus has been on expanding the material library developed, adopting a bottom-up approach to synthesize a diverse range of hybrid electrolytes. The evaluation of these materials involved the utilization of silicon nanoparticles (si-NP) with different sizes and surface functionalities, combined with polymer chains featuring various functionalities and lengths. Our objective was to assess the performance of these hybrid electrolytes.
A key aspect of our work involved studying the structural organization through hierarchical self-assembly of low-dispersity high-nanoparticle (HNP) nanosized building blocks into prescribed nanoparticle superlattices. This approach aimed to create artificial solids featuring inherently Li+-conducting paths spanning nano to meso to microscopic scales. The minimalized structural variations considered parameters such as the inorganic core diameter, thickness of the ionically conducting polymeric shell, and variation of lithium salt loadings.
The outcomes of this work have allowed for the creation of mini-libraries comprising almost ideal model systems.
In summary, the work performed from the beginning to the present stage of the project has been dedicated to the synthesis, evaluation, and thorough characterization of hybrid electrolytes. The achieved results have provided valuable insights into the structural and transport properties of these materials, laying the foundation for further advancements in the field of solid-state hybrid electrolytes.

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)

This project represents the early stages of a case study, specifically focusing on a promising self-healing chemistry—the seminal Diels-Alder chemistry—as a potential solution for the next generation of polymer-based all-solid-state batteries (ASSBs). Our aim is to glean insights into the electrochemistry of self-healing polymer electrolytes, employing a key-enabling research methodology.
As we progress, we delve into the intriguing aspect of using temperature as a physical parameter to implement Diels-Alder/retro-Diels-Alder (DA/rDA) cycles. This exploration holds implications for a battery management system (BMS) 2.0 tailored for ASSBs. Our ultimate goal is to pave the way for the realization of self-healing batteries (SHBs), contributing to a circular ASSB economy. We also highlight the compatibility of this approach with "chemistry-neutral" strategies, making it applicable to both mono and multi-valent cations in the context of next-generation batteries.
As the project evolved, we expanded our material library using a bottom-up approach, synthesizing diverse hybrid electrolytes. This entailed the utilization of silicon nanoparticles (si-NP) with varied sizes and surface functionalities, combined with polymer chains of different functionalities and lengths. The goal was to comprehensively assess the performance of these hybrid electrolytes.
Our outcomes have resulted in the creation of mini-libraries comprising almost ideal model systems. These systems are essential for probing nanoconfined ionic transport within solid-state hybrid electrolytes. To master key performance indicators (KPIs) such as conductivity, electrochemical stability window (ESW), and lithium ion transference number (t+Li), we pursued comprehensive multi-scale/physics structure/property correlations, utilizing a set of complementary techniques across relevant length scales and timescales.
In conclusion, the work performed thus far in the HOPES project has laid the groundwork for understanding and harnessing the potential of self-healing chemistries and temperature-driven cycles in the development of advanced polymer-based all-solid-state batteries. We also highlight the compatibility of this approach with "chemistry-neutral" strategies, making it applicable to both mono and multi-valent cations in the context of next-generation batteries.

Schematic implementation of the HNPs-based materials platforms into self-assembled SSHEs