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254 records · Page 15

Effect of Fluoride Anions on Nd(III) Electrode Processes and Nd Metal Recovery in LiCl–KCl–NdCl 3

Here, this work investigated the impact of fluoride anions on Nd metal recovery in LiCl–KCl–NdCl 3 electrolytes by introducing LiF at a molar F/Nd ratio of 9 at 773 K. The voltammetric measurements confirmed that the fluoride ions facilitated single-step Nd(III)/Nd reduction by promoting the stability of the Nd(III) state compared to two-step reduction (Nd(III)/Nd(II) and Nd(II)/Nd) in all-chloride electrolytes. The stabilized Nd(III) state in the LiF-containing electrolyte effectively suppressed partial Nd(III)/Nd(II) reduction and the back-dissolution of Nd metal via comproportionation. By suppressing these reactions, high round-trip Coulombic efficiencies of 77–86% were achieved in the LiF-containing electrolyte during selective Nd deposition–removal cycles compared to 53–59% in all-chloride electrolytes. The Faradaic yield for Nd metal recovery was estimated at 38.6% in the LiF-containing electrolyte following long-term electrolysis, more than three times higher than 11.3% in all-chloride electrolytes. These results confirm the beneficial effect of fluoride ions on Nd metal recovery in low-melting chloride-based electrolytes, promising efficient Nd recovery at low temperatures.

11 - NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Grand challenges and opportunities in next-generation batteries and technologies

The development of advanced Li-ion batteries and technologies generally addresses one of four objectives: 1) create a higher volumetric energy density and/or specific energy/power, 2) impart intrinsically safer chemistry, 3) produce speedier charging, and 4) utilize less expensive batteries but with competitive/near-competitive performances. Certainly, other factors can play a role as well, dependent on the type of market targeted and the availability of global supplies; however, for widespread adoption, the above points/criteria remain salient. Li-ion is commercially well entrenched in industry for communication and transportation (EV) applications. Nowadays, slight iterations, mostly electrolyte-defined, are incrementally improving safety, cost, and cycle or calendar life. The last point, calendar life, is one that is often overlooked for very high-energy dense Li-ion batteries, because of their reactivity at higher charge (OCV conditions) and elevated temperatures. While cycle life is debated with respect to capacity/energy performance decline, attempts to re-purpose the battery itself or recycle the internal chemical constituents at end of life have considerably grown in the field. Hopefully, energy-neutral processes are also considered in the recycling loop. Nevertheless, the energy storage arena is quite large, and this pursuit hinges on pushing the field in one of many directions, toward loftier objectives. The pursuit of next-generation batteries and technologies must thus delve deeper into new and novel chemistry and electrochemistry to create a world with a neutral, carbon-free environment, and one that is solely sufficient on energy-producing renewables such as the Sun and wind-derived means. The application of electricity and chemistry within our world is thus a 21st century opus.

25 ENERGY STORAGE↗