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Although deep eutectic solvents (DES) and ethylene glycol (EG) electrolytes are gaining ground as media for the electrodeposition of metals, the influence of these electrolytes on the electrode and electrodeposits has not been elaborated before. In this work, we investigate how choline chloride: ethylene glycol based (ChCl:EG) electrolytes interact with the glassy carbon (GC) working surface at different potentials and, how these interactions change during the electrodeposition of iron from 1:2 and 1:4 ChCl:EG electrolytes. GC substrates are exposed to both electrolytes in absence of iron in order to study the pure electrolyte-substrate interactions. Linear sweep voltammetry was used to determine the potential range in which the different reactions occur, while time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used to detect and identify the molecules adsorbed on the surface. In all systems, there is an accumulation of either choline or its derivatives on the electrode surface, with 1:4 ChCl:EG electrolytes showing different decomposition products from 1:2 ChCl:EG electrolytes. Choline accumulation and decomposition was also found on iron electrodeposits. The electrolyte composition has a major impact on the chemical speciation of iron, and on the deposit's adherence to the substrate. These are two crucial characteristics that define the efficiency of iron deposition from DES.

Being successfully introduced into the market only 30 years ago, lithium-ion batteries have become state-of-the-art power sources for portable electronic devices and the most promising candidate for energy storage in stationary or electric vehicle applications. This widespread use in a multitude of industrial and private applications leads to the need for recycling and reutilization of their constituent components. Improving the “recycling technology” of lithium ion batteries is a continuous effort and recycling is far from maturity today. The complexity of lithium ion batteries with varying active and inactive material chemistries interferes with the desire to establish one robust recycling procedure for all kinds of lithium ion batteries. Therefore, the current state of the art needs to be analyzed, improved, and adapted for the coming cell chemistries and components. This paper provides an overview of regulations and new battery directive demands. It covers current practices in material collection, sorting, transportation, handling, and recycling. Future generations of batteries will further increase the diversity of cell chemistry and components. Therefore, this paper presents predictions related to the challenges of future battery recycling with regard to battery materials and chemical composition, and discusses future approaches to battery recycling.

Point-of-care detection is a widely studied area that attracts effort and interest from a large number of fields and companies. However, there is also increased interest from the general public in this type of device, which has driven enormous changes in the design and conception of these developments and the way data is handled. Therefore, future point-of-care detection has to include communication with front-end technology, such as smartphones and networks, automation of manufacture, and the incorporation of concepts like the Internet of Things (IoT) and cloud computing. Three key examples, based on different sensing technology, are analyzed in detail on the basis of these items to highlight a route for the future design and development of point-of-care detection devices and their data capture and handling.

The fine tuning of deep eutectic solvents (DES) via the addition of co-solvents such as water or excess ethylene glycol, to improve the electrodeposition of metals is becoming increasingly common. However, as these changes become commonplace, our understanding of their effect must deepen as well. In this work, we look into how water, a secondary hydrogen bond donor (HBD), added to choline chloride:ethylene glycol (1:2 ChCl:EG) DES changes the electrochemical behaviour of the solution. We use time-of-flight secondary ion mass spectrometry (ToF-SIMS) to identify and map the organic molecules that have interacted with the surface. A copper surface was used as an electrochemically active substrate. The molecular maps provide insights into how solvent composition changes electrolyte reactivity, as well as showing the main driver behind the entrapment of organic compounds in metal deposits from DES. This behaviour was studied at different potentials based on the information provided by linear sweep voltammetry data of the copper in the solution. These results are then contrasted against a 1:4 ChCl:EG solution, where the excess ethylene glycol acts as secondary HBD, in order to determine the individual contributions of the co-solvents and how they affect the electrochemistry of the media and their reactions with the copper electrode. This information can be used as a set of guidelines for the tuning and optimisation of ethylene glycol based DES for metal deposition.