Perspectives For Next Generation Lithium

Costs will be reduced by systematically reducing/ultimately eliminating cobalt-content. The consortium is also discovering new chemistries and developing protective coatings/additives to extend lifetimes and reduce costs. Diaphragm cells consume less energy per ton of product than do mercury cells, but the caustic soda produced from mercury cells is purer than that from diaphragm cells. The primary objectives in developing the membrane cell have been to produce caustic soda of a quality at least as good as that from the mercury cell with energy efficiency as good as, or better than that of the diaphragm cell. Among 3d transition metals, nickel ensures higher cell voltage and a continuous voltage profile, as well as a delocalized electron density i.e., good electronic conductivity.

The recently announced EU Battery Regulation proposes all new batteries sold in Europe from 2030 must meet the minimum threshold of 4% Nickel, 12% Cobalt & 4% Lithium, by weight, of recycled materials. Lithium ions diffuse in 2 dimensional planes separated by CoO2 layers.It is the most widely used cathode material in consumer electronics since SONY first introduced it in 1991. However, by performing careful operando x-ray studies that circumvented beam damage and observe only trace amounts of Mn7+ forming upon charging in Li-excess cathodes during battery cycling. Their findings, reported in a paper in ACS Energy Letters, support theories Tang and his colleagues formed several years ago that foresaw how lithium travels in the dynamic environment inside a typical commercial cathode. Being able to watch sealed cathodes charge and discharge at Brookhaven offered absolute proof.

It includes work to understand the origins of the current limitations of nickel-rich cathodes and to understand the fundamental electrochemistry of lithium-rich oxygen redox cathodes. The project is exploiting this new knowledge to inform the discovery of novel cathode materials with enhanced properties. The most promising materials will be identified, before scaling up their synthesis and integrating them in full battery cells to demonstrate performance. The project will support the accelerated development of new cathode materials towards practical commercial applications. From a consideration of its low hydrogen overpotential and its chemical stability there has always been a possibility that platinum could be incorporated into a chloralkali cathode with advantage. The primary objective of this paper has been to show that this can now be done with economic benefit.

Despite their relatively high cost, the noble metals have an important role to play in the chloralkali industry. Nowadays graphite is rarely used as an anode material, having been almost totally superseded by titanium coated with a noble metal, usually ruthenium. A typical diaphragm cell catholyte contains about 15 per cent caustic soda and 20 per cent sodium chloride. In order to produce caustic soda which is acceptable to industry, the sodium chloride has to be removed.

The noble metal coating is neither electrolytic, nor is it an electroless plate in the conventional sense. Most properly the operation can be described as an immersion plating process depending for its effect on the relative redox potentials of the metals involved. Johnson Matthey Chemicals Limited now has the capacity to treat some 25,000m2 of area per year at its Royston factory.

But this comes with a caveat – the adverse impact on the thermal stability and long-term cycling performance. Residual Li form on the surface of a Ni-rich compound over time when exposed to air, which is detrimental to electrode slurry making and cyclability. With the surge of electric vehicles , development of low-cost, high energy density batteries is a necessity. High energy density cathodes have garnered tremendous interest as they hold the key to high energy density lithium-ion batteries which are needed to overcome ‘range anxiety’ that is holding back universal uptake of EVs.

Under working conditions emission is limited by the space charge; to measure the total emission there must be no such limiting factor. It is also desirable that the cathode temperature should be low enough for ionic equilibrium to be maintained within it. The method developed is to use the control grid as collector, making its potential +5V and earthing the other electrodes; for 6.3-V valves the heater is at about 2.6V.