ACS Applied Energy Materials Paper Published
An investigation of eutectic electrolyte mixtures for low-temperature aluminium batteries led by Jonah Wang was published today. This work uses a combination of NMR spectroscopy and electrochemical methods to understand the electrolyte speciation and monitor the cycling performance, both for electrodeposition, and also in aluminium-graphite cells. We show operation down to -40 ℃ in the ternary AlCl3-urea-[EMIm]Cl mixture at a mole ratio of 1.3-0.25-0.75. In addition to supressing the freezing point, the addition of urea to the binary mixture of AlCl3-[EMIm]Cl improves the cost effectiveness of such electrolytes.
ACS Materials Letters Paper Published
We just published a fundamental investigation of selenium structure at different length scales and how it affects the electrochemical reactions achieved in aluminium-selenium batteries. To achieve a full 6-electron capacity of selenium electrodes in aluminium batteries, it is imperative that the Se(0) to Se(–II) is attainable as well as the Se(0) to Se(IV) reactions. This paper documents the viability of the selenium to aluminium selenide electrochemical reduction in glassy selenium, which is seldom observed with crystalline trigonal selenium. This paper challenges the naive assumption that aluminium batteries using sulfur and selenium cathodes would operate in the same way. While both are chalcogens, the bonding topologies of elemental selenium and sulfur are quite different in their most stable forms (trigonal Se chains vs. 8-membered S rings) and this leads to differences in their electrochemical performances.
ACS Macro Letters Paper Published
Our recent paper led by James Bamford demonstrates the improvements in mechanical strength after adding nickel salts to a coordinating, imidazole-containing polymer. The study demonstrates that even with addition of NiTFSI2 up to r=0.16, ionic conductivity of Li+ is not strongly affected, however, the increase in mechanical stiffness is notable as a result of dynamic crosslinking of imidazole functionalities with Ni2+. This demonstrates that ion transport and bulk mechanics can be decoupled by the addition of multivalent metal cations to polymers with chelating ligands.