Ionic liquid chloride cathode

They found that lithium chloride was not soluble in the neutral but dissolved in the neutral acidic ionic liquid. From the latter no reduction of lithium was observed prior to the cathodic limit of those ionic liquids. Thus they prepared first the neutral acidic ionic liquid with a certain excess of AICI3 and then added an equivalent amount of lithium chloride to obtain a LiAlCU solution in a neutral ionic liquid. From that they were able to reduce lithium ions on tungsten, glassy carbon, and aluminum electrodes. 

Early in their work on molten salt electrolytes for thermal batteries, the Air Force Academy researchers surveyed the aluminum electroplating literature for electrolyte baths that might be suitable for a battery with an aluminum metal anode and chlorine cathode. They found a 1948 patent describing ionicaUy conductive mixtures ofAlCh and 1-ethylpyridinium halides, mainly bromides [6]. Subsequently the salt 1-butylpyridinium chloride -AICI3 (another complicated pseudo-binary) was found to be better behaved than the earlier mixed halide system, so the chemical and physical properties were measured and published [7]. I would mark this as the start of the modern era for ionic liquids, because for the first time a wider audience of chemists started to take interest in these totally ionic, completely nonaqueous new solvents. 

An attempt has been made [17] to summarize the results on the electrochemical behaviour of TiCLt in disubstituted imidazolium-based ionic liquids with bis (trifluoromethylsulfonyl) imide (Tf2N) anion. The authors [17] came to very interesting conclusion the reduction of Ti(lV) to Ti metal is essentially impossible in the presence of chloride ions because of the low solubility of the titanium chloride intermediates, which deposit on the cathode in the form of non-stoichiometric halides instead of elemental Ti. Thus, in fact, the electrochemical reduction process of titanium (IV) in these ionic liquids was implicitly recognised to proceed in three-phase system electrolyte-film-metal. 

Cojocaru, A. Costovici, S. Anicai, L. Visan, T. (2009), Studies of cathodic processes during NiSn alloy deposition using choline chloride based ionic liquids, Metalurgia International, Vol.l4, No.ll, pp. 38-46, ISSN 1582-2214... 

Yoon et al. [48] proposed a liquid junction free polymer membrane-based reference electrode system for blood analysis under flowing conditions. They used silicmi wafers as well as ceramic substrate to fabricate ion selective sensors with an integrated reference electrode. The silver chloride layer was coated with a membrane based on aromatic polyurethane (PU 40 membrane) with equimolar amounts of both cathodic and anodic lipophilic additives (TDMACl and KTpCIPB) to reduce the electrical resistance (see Chaps. 12 and 13). The ceramic-based sensors were fabricated by screen-printing methods. Both reference electrodes showed a rather stable potential in various electrolyte solutions with different pH values and different concentrations of clinically relevant ions, providing that the ionic strength of the solution is over 0.01 M. The integrated ISE cartridge based on the ceramic chip could be used continuously for a week. 

---