Layered Hydroxides for advanced energy storage devices – LaDHy
The introduction of an ever-increasing amount of intermittent energy production onto the electrical grid will require more flexibility, which can be obtained by installing “buffers” in the form of electrical storage. Amongst today’s decentralised solutions, neither batteries nor supercapacitors provide satisfactory solutions to meet the full specifications of the network operator, particularly with regard to the power and energy density, cyclability, safety, recycling and cost. The LaDHy project (Layered Hydroxides project for advanced energy storage devices) aims at developing an innovative electrochemical energy storage technology, which bridges the gap between batteries and supercapacitors, and capable of delivering or absorbing power peaks for 15 minutes for frequency regulation purposes. The novelty of the project will be to develop electrodes with fast and reversible faradic reactions using redox species trapped in a layered hydroxide matrix, single or double (LSH, LDH). These are mixed hydroxides of divalent and trivalent cations (divalent only for LSH’s) with anionic species intercalated between the hydroxide layers. Energy storage is obtained not only by trapping electroactive anions between the layers, but also by using electro-active cations in the layered hydroxide framework itself. LDH’s and LSH’s have the ability to incorporate a wide variety of anions, and a wide variety of mainstream applications can result, from agriculture for the release of nutrients to de-icing additives for asphalt mixtures. The additional advantage of LSH’s is its ability to anchor iono-covalent anions to the LSH sheets thus producing stronger bonds than in the LDH’s. This variation in property between the two types of layered hydroxides will be exploited to fine-tune the properties of the final material and optimise its electrochemistry and stability on cycling. Intercalated quinone anions displaying a broad potential window also offer the possibility to use these LDH/LSH’s for both electrodes. The relatively inexpensive and low temperature (low energy) synthesis, the use of an aqueous electrolyte and the good recyclability of these layered hydroxides make them an attractive, clean and sustainable solution, suitable for large-scale applications. The use of aqueous electrolytes will also provide greater safety of storage devices compared to current batteries and supercapacitors operated mostly in organic, flammable and potentially toxic media.
The LaDHy project brings together two academic laboratories and an industrial partner. ICCF is specialized in the synthesis of tailored LDH and IMN in the formulation and characterization of new electrode materials for batteries, supercapacitors or hybrid systems. The EDF group is a global leader in low-carbon energy production. It covers all businesses spanning the whole electricity value chain – from generation to distribution and including energy transmission. It has drafted the requirements for this new device and it has validated the adequacy of the solution proposed in the LaDHy project. The project will include the synthesis of innovative LDH and LSH/redox active compounds and their integration into optimised electrodes. The best materials will be used to make 18650 demonstrator cells which will be tested with real load curves obtained from EDF’s measurements on the field to demonstrate their ability to fulfil the grid services they are designed for. The more applied research will be accompanied by fundamental studies to understand and explore the interactions between LDH/LSH’s and redox active anions. The past experience as well the characterisation and prototyping platforms available to the partners makes this ambitious project realistic. It will bring these new ideas from a TRL1-2 to a TRL of 4-5 and could pave the way to a new type of storage and new markets for electricity storage.
Monsieur Thierry BROUSSE (INSTITUT DES MATERIAUX JEAN ROUXEL)
The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.
EDF SA ELECTRICITE DE FRANCE DIRECTION R&D
ICCF INSTITUT DE CHIMIE DE CLERMONT-FERRAND
IMN INSTITUT DES MATERIAUX JEAN ROUXEL
Help of the ANR 448,965 euros
Beginning and duration of the scientific project: November 2020 - 42 Months