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A method for the synthesis of phenylphosphonic acid functionalized poly[aryloxyphosphazenes] is described. Diphenyl chlorophosphate was used as the phosphonating agent and was allowed to react with lithio-functionalized aryloxyphosphazenes, followed by treatment with aqueous sodium hydroxide. Subsequent acidification with aqueous hydrochloric acid yielded phenylphosphonic acid functionalized poly[aryloxyphosphazenes]. These polymers are candidates for use as proton-conducting membranes in fuel cells.

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Combining the use of nickel-rich layered oxide cathode materials with the implementation of aqueous electrode processing can pave the way to cost-reduced and environmentally friendly electrodes and simultaneously increase the energy density of cells. Herein, LiNi0.33Co0.33Mn0.33O2 (NCM111), LiNi0.6Co0.2Mn0.2O2 (NCM622), LiNi0.8Co0.1Mn0.1O2 (NCM811) and LiNi0.8Co0.15Al0.05O2 (NCA) were evaluated in terms of their response to aqueous processing under the same conditions to facilitate a direct comparison. The results illustrate that mainly nickel driven processes lead to lithium leaching which is combined with the increase of the pH value in the alkaline region. For NCA an additional aluminum-involving lithium leaching mechanism is assumed, which could explain the highest amount of leached lithium and the additional detection of aluminum. Electrochemical tests show a reduced capacity for cells containing water-based electrodes compared to reference cells for the NCM-type materials which increases during the first cycles indicating a reversible Li+/H+-exchange mechanism. In contrast, the NCA cells were completely electrochemically inactive making NCA the most water sensitive material tested in this report. By comparing the cycling performance of cells containing aqueous processed electrodes, a more pronounced capacity fade for nickel-rich cathode materials as compared to their reference cells can be observed.

Two methods for the addition of pendent dialkyl phosphonate units onto aryloxyphosphazenes, at both the polymeric and cyclic trimer levels, are described. Sodium organophosphites or halogenated organophosphates were used as the phosphonating agents and were allowed to react with bromomethylene- or lithio-functionalized aryloxyphosphazenes, respectively. Phosphonation of bromomethylene−phenoxy side groups proceeded with ∼100% conversion, while phosphonation via lithiophenoxy intermediates yielded 80−85% conversion. The presence of a direct phosphorus−carbon bond in all products was confirmed by 13C NMR. Well-defined, cyclic trimers and polymers were obtained via both methods.