Kothandaraman Ramanujam

In the context of solid-state electrolytes for batteries, ambient temperature ionic conductivity stands as a pivotal attribute. This investigation presents a compilation of potential candidates for solid-state electrolytes in lithium-ion batteries, employing clustering—an unsupervised machine-learning technique. To achieve this, a fusion of data from two distinct datasets was undertaken: a smaller dataset consisting of 51 compounds endowed with experimental lithium-ion conductivity data and a substantially larger dataset of 15,530 compounds devoid of such information. The compounds in our dataset were divided into various groups based on several characteristics that influence the conductivity of lithium-ion batteries. Then, the location of the compounds known to have high lithium-ion conductivity (>10−4 S cm−1) at room temperature was observed. The 427 compounds (i.e., unique material project IDs) found in the same cluster as most of these high-conducting compounds are then further examined. This paper concludes by offering a catalog of solid-state compounds that can be utilized to choose compounds for solid-state electrolytes in batteries. Graphical Abstract: Synopsis: The above plot shows the 15530 lithium-based compounds clustered into 7 clusters based on several factors that were identified to affect lithium-ion conductivity. We observe the location of the already known good lithium-ion conductors (represented by the golden stars) to identify other similar compounds. (Figure presented.)

Energy security and sustainable energy are becoming more crucial in the current situation. As a result, fuel cells and metal-air batteries have recently received a lot of interest. However, these devices' main drawbacks are the slowness of the oxygen reduction reaction (ORR) and the expense of the catalyst. The necessity for high-performance noble-metal-free electrocatalysts is therefore urgent. This paper describes a CuOx-Co3O4-based heterostructure with nitrogen-doped carbon support (Cu/CuOx-Co3O4/NC-700) as an effective, durable, inexpensive ORR catalyst. The catalyst exhibits good ORR activity with a half-wave potential of 0.81 V vs. RHE with a 6.5 mA cm−2 limiting current density. The observed ORR performances are comparable with benchmark Pt/C catalysts. The Zn-air battery (ZAB), utilizing the synthesized Cu/CuOx-Co3O4/NC-700 catalyst, produces a high open circuit voltage (OCV) of 1.41 V. The catalyst also exhibits a superior specific capacity of 820 mAh gZn−1 and a higher peak power density of 103 mW cm−2. Cu/CuOx-Co3O4 and NC have a strong synergistic impact and are responsible for the enhanced ORR activity. Hence, Cu/CuOx-Co3O4 heterostructures introduced oxygen vacancies, high surface area, desirable charge transfer, and unsaturated chemical bonds in the interface to create a charge redistribution. As a result, the catalytic activity has improved significantly.

Industrially ammonia (NH3) is produced from the energy-intensive Haber-Bosch (HB) process. Electrochemical nitrogen reduction reaction (eNRR) is often hailed as a possible alternative to the HB process, as it has lower energy requirements and can reduce N2 to NH3 at ambient conditions. In this review, 50 catalysts for eNRR synthesised within the last three years are judged based on the energy economics and yield rate, to determine if they could be a suitable alternative to the HB process.