Engineering Robust Cathodes for Sustainable Energy Storage
Lead Research Organisation:
Brunel University London
Department Name: Chemical Engineering
Abstract
Energy storage devices such as batteries and capacitors have become an integral part of our daily life and there is a tremendous zeal to accelerate this technology to be used in electric vehicles and grid storage. It also plays a vital role in mitigating climate change, and enables a low carbon economy by storing and utilising the energy generated from renewable resources. Although lithium ion batteries (LIBs) have dominated the market from 1990's, the shortage of resources and challenges faced in recycling LIBs which contain hazardous and reactive materials will have a detrimental effect on UK and make it dependent on external markets. Therefore, there is an urgent need to develop energy storage devices with environmentally benign and sustainable materials that are easy to recycle which would lead the way to a circular economy. In this regard, Zn ion capacitors (ZICs) offer a sustainable, cost-effective (cost-per-kWh) and safe energy storage system which is also easy to recycle.
Building on our previous work on using vitamin based ionic liquid electrolytes in batteries that are environmentally benign, the current project aims at developing Zn ion capacitors (ZICs) having high energy and power densities. This would lead ZICs to charge at a faster rate and store more energy. As an emerging topic, the major challenge in ZICs is the size and charge of Zn ions which are difficult to store at the cathode and leads to lower capacity and limited cyclability. Therefore, the project aims at
1. Developing suitable hybrid cathodes with 2D porous carbon embedded with transition metal oxides that can improve electronic conductivity and diffusion kinetics of Zn ions to obtain high power density, and also inducing storage sites in the cathode to obtain high energy density.
2. Understanding the Zn storage mechanism and impedimental reactions which take place in the capacitors by in situ measurement techniques in collaboration with Diamond Light Source.
3. Modulating the cathode to mitigate the impedimental reactions and improve the ZIC performance.
4. Engaging with project partners (TWI) for scale-up and implementation
Building on our previous work on using vitamin based ionic liquid electrolytes in batteries that are environmentally benign, the current project aims at developing Zn ion capacitors (ZICs) having high energy and power densities. This would lead ZICs to charge at a faster rate and store more energy. As an emerging topic, the major challenge in ZICs is the size and charge of Zn ions which are difficult to store at the cathode and leads to lower capacity and limited cyclability. Therefore, the project aims at
1. Developing suitable hybrid cathodes with 2D porous carbon embedded with transition metal oxides that can improve electronic conductivity and diffusion kinetics of Zn ions to obtain high power density, and also inducing storage sites in the cathode to obtain high energy density.
2. Understanding the Zn storage mechanism and impedimental reactions which take place in the capacitors by in situ measurement techniques in collaboration with Diamond Light Source.
3. Modulating the cathode to mitigate the impedimental reactions and improve the ZIC performance.
4. Engaging with project partners (TWI) for scale-up and implementation
People |
ORCID iD |
| Abhishek Lahiri (Principal Investigator) |
Publications
Lahiri A
(2024)
Effect of Water on Zn Electrodeposition from a Deep Eutectic Solvent
in Journal of The Electrochemical Society
| Description | The project currently has looked into optimising the electrolyte composition of new deep eutectic solvent which can be used in Zn-ion capacitors. It was observed that the concentration of water in the deep eutectic solvent plays a critical role in Zn deposition and therefore would influence the battery performance. Furthermore, besides water, the Zn salt used also plays a critically role which affects the Zn-ion capacitor performance. The anions of the zinc salt was found to interact differently which changed the reaction mechanism and thus the capacitor performance. This fundamental study opened up new avenues for looking into new capacitor chemistry. The next part of the work is to optimise the cathode chemistry which is being undertaken to develop a high energy density Zn-ion capacitor. |
| Exploitation Route | Once we fundamentally understand the reaction mechanism in different cathode/electrolyte composition, an optimised composition can then be fabricated to develop new high energy density Zn-ion capacitors. |
| Sectors | Energy |
| Title | Data of Zn polymer battery studied in different electrolytes |
| Description | This is the raw data set of XPS and fitted peaks to different components, IR and in situ Raman spectra of polymer at different potentials, cyclic voltammetry and battery charge discharge data in different deep eutectic solvent electrolytes. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2024 |
| Provided To Others? | Yes |
| Impact | Based on all the dataset and the study it was found that Chlorine and triflate anions in the electrolyte resulted in better Zn-ion capacitor stability. Furthermore, the mechanism of Zn interaction with the polymer was established. |
| URL | https://brunel.figshare.com/articles/dataset/Data_of_Zn_polymer_battery_studied_in_different_electro... |
| Title | IR, Raman spectra along with the cyclic voltammetry data for different electrolytes |
| Description | This is the raw data set of IR and Raman spectra of different deep eutectic solvent electrolytes in presence of water. Also, it include the electrochemical cycling of these electrolytes on copper. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2024 |
| Provided To Others? | Yes |
| Impact | In this dataset we studied the influence of water in a deep eutectic solvent and its effect of Zn solvation and Zn deposition. It was found that below 30% water in the deep eutectic solvent, the Zn coordination number which changed to higher values with more water. At lower water concentration, the Zn morphology was porous which changed to a thick morphology on increase in water concentration. Based on this study, it was established that a water concentration of greater than 30% of water in deep eutectic solvent would lead to better Zn deposit which would improve the Zn-ion capacitor performance |
| URL | https://brunel.figshare.com/articles/dataset/IR_Raman_spectra_along_with_the_cyclic_voltammetry_data... |
| Description | Collaboration with diamond light source |
| Organisation | Diamond Light Source |
| Country | United Kingdom |
| Sector | Private |
| PI Contribution | We developed MnO2 cathode materials to be tested for zinc ion capacitors. To understand the detailed reaction mechanism, in situ and ex situ XAS were performed at diamond light source. |
| Collaborator Contribution | The collaboration partners helped us a lot in lending us their fabricated electrochemical cell. This is a new setup at B07 in diamond light source which we were one of the first few to try out to measure battery/capacitor electrodes. Besides, the gold coated Si3N4 samples were provided by the partners. Throughout the experimental time provided to us (144 hours), the collaborators helped us in performing the experiments, developing the setup and providing us with their expertise and experience. As the experiments are very complicated, their help was crucial in generating the results which we intend to publish shortly. |
| Impact | The main output of the collaboration was a detailed understanding of Mn oxidation states in MnO2 at different electrochemical potentials. We performed two different experiments. The ex situ experiments gave us the best results on which we are working and we will publish these results shortly (by mid 2024). The experiments were performed in three different electrolytes consisting of aqueous solution (1M Zn acetate) and bio-ionic liquid electrolytes (Choline acetate) and Choline iodide. As electrochemical experiments showed a change in electrochemical behaviour, XAS studies are crucial to identify the changes in the MnO2 cathode. The in situ results were more complicated and an issue with the measurements were noted during the experiment which no one was aware. The main issue with the in situ experiment was Mn does not provide any fluorescence spectra and for in situ XAS experiments, these fluorescence spectra are crucial. Therefore, in situ experiments could only reveal the oxygen spectra from which it was very difficult to bring out the oxidation states of Mn. Therefore, future in situ experiments are being planned with the cathode materials which show fluorescence spectra. |
| Start Year | 2022 |
| Description | Open day participation |
| Form Of Engagement Activity | Participation in an open day or visit at my research institution |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Public/other audiences |
| Results and Impact | The department of Chemical engineering organises open days to the public at least twice a year in which general public is invited to visit the department to see the research facilities and ongoing research. During these visits, I explain the need for developing sustainable batteries and talk about my current running projects. I focus on the project of developing Zn-ion capacitors and need for these capacitors and how the development of these new energy storage devices would benefit the industry and society. During such visits, I show them the lab and talk to them by showing some of the results. Besides, our department has a industrial advisory board and we have meetings at least twice a year. During these meetings, we talk to the board members about the current projects, show them the lab facilities and how the project is progressing. |
| Year(s) Of Engagement Activity | 2022,2023 |