Electrowinning of Lithium from LiOH in Molten Chloride

Abstract

An investigation was carried out to determine the viability of electrowinning lithium from LiOH in molten chloride, with a view to developing a system for the storage and transportation of hydrogen using LiH as the storage medium. It was predicted from the chemical potential diagram for the Li-O-H system that Li metal cannot be electrowon from a LiOH-containing salt, as any Li generated by electrolysis will readily react with LiOH to form Li 2 O. Electrolysis in molten LiCl-42 mol% KCl or molten LiCl-17 mol% KCl-26 mol% CsCl was therefore utilized, in which LiOH was fed into an anode compartment separated from the Li metal deposited at the cathode by a porous magnesia diaphragm, thereby preventing the transportation of LiOH into a cathode compartment. Using this arrangement, Li metal was successfully obtained with a cathode current efficiency of 84-86%. The generation of CO 2 at the graphite anode was also found to decrease with decreasing electrolysis temperature when using a chloride melt with a lower eutectic temperature. Hydrogen storage materials.-Hydrogen energy is expected to offer a number of advantages in terms of providing high energy efficiency through the use of fuel cells and a reduction in the environmental impact of CO 2 and NO x emissions; however, there has as yet been no effective, large-scale supply system established for hydrogen. The most promising methods for the storage and transportation of hydrogen that are currently under development have been briefly reviewed in a previous article by the authors, 1 in which it was revealed that the large hydrogen-storage capacity of LiH can provide a compact medium ideally suited to transportation. In light of this, we herein present a novel system for the storage and transportation of hydrogen that is based on using LiH as the storage medium.

Flexible and stable high-energy lithium-sulfur full batteries with only 100% oversized lithium

“…It has been pointed out lately that a critical challenge for Li-S batteries is achieving high energy density and high stability in a full cell with the use of a Li anode that is only 6 mA h cm −2 in size (~100% oversize) 38 . This is also of remarkable importance from a sustainability point of view, as the production of Li is environmentally unfriendly and expensive 39 . Until now, high energy density and stable cycling has not been achieved in a flexible Li-S full cell with a limited source of Li.…”

From Lithium‐Metal toward Anode‐Free Solid‐State Batteries: Current Developments, Issues, and Challenges

“…Fluctuations in the price of metallic lithium create cost issues for Li-metal batteries. [49] In anode-free configuration, the minimum amount of Li required for operation is stored inside the cathode, which can be produced using lithium compounds such as Li 2 CO 3 or LiOH, whereas metallic Li anodes require much higher purity (e.g., by energy-intensive electrolysis [50] ). Based on the cost model of Schmuch et al [41] anode material costs amount to approximately 20% in the case of LIB, and 33-57% in the case of LMSSB (N/P = 3).…”

A critical review on the practical use of lithium cycle as an upfront nitrogen removal technology from natural gas

“…This uses up some of the electric currents, which leads to a decreased current efficiency as suggested by Laude et al 25 The current efficiencies in the electrolysis of LiOH were reported to range from 38% 25 up to >80%. 26,27 Given the nature of such reactions discussed in this section, it is concluded that such a pathway that starts with lithium metal and undergoes a regeneration cycle for continuous operation in an LNG plant is theoretically possible with attention to the highlighted details and the concerning reaction conditions. Some of these conditions include temperature, pressure, and energy requirements.…”