Copper-ion solid-state battery systems involving sulphonium iodide electrolytes
THE past 10 years has seen a considerable interest in solid-state battery systems involving electrolytes based on silver iodide1–3. Studies of electrolytes involving organic sulphonium iodides in conjunction with silver iodide have been reported3,5–9, but recently the possibility of using cuprous ions to replace silver ions as the mobile species has attracted attention, because of the potential advantage of lower cost and higher voltage. We report here the results of our investigations of sulphonium iodide–cuprous iodide electrolytes.
Electrical Transport Studies of Copper Mercuric Iodide
Measurements are given of electrical conductivity (σ) and thermoelectric power (S) of copper mercuric iodide (Cu2HgI4) (which becomes a solid superionic conductor above 344 K) are reported both, in the α- and β-phase. In the α-phase it behaves as a Cu+-ion solid superionic conductor in the temperature range 345 to 410 K. The heat of transport (Q) and activation enthalpy (hm) for Cu+ ions in this phase both are found to be equal to 0.11 eV. These results are explainable by free ion as well as lattice gas models. In the β-phase (below 344 K) the electrical conductivity is mainly extrinsic. In relatively pure material, it is due to interstitial Cu+ ions whose heat of transport and activation enthalpy are evaluated to 0.27 and 0.28 eV, respectively. 
 
 
 
Es werden die Mesergebnisse der elektrischen Leitfahigkeit (σ) und der Thermospannung (S) von Kupferquecksilberjodid (Cu2HgI4) (das oberhalb 344 K ein fester Superionenleiter wird) sowohl in der α- als auch in der β-Phase mitgeteilt. In der α-Phase verhalt es sich als fester Cu+-Ionen-Superionenleiter im Temperaturbereich 345 bis 410 K. Die Transportwarme (Q) und die Aktivierungsenthalpie (hm) fur Cu+-Ionen werden in dieser Phase zu 0,11 eV gefunden. Diese Ergebnisse lassen sich erklaren sowohl durch freie Ionen als auch mit Gitter-Gasmodellen. In der β-Phase (unterhalb 344 K) ist die elektrische Leifahigkeit hauptsachlich extrinsisch. In relativ reinem Material wird sie durch Cu+-Zwischengitterionen hervorgerufen, deren Transportwarme und Aktivierungsenthalpie zu 0,27 bzw. 0,28 eV bestimmt werden.
The Effects of Certain Polymers on Tensile strength and Tension Relaxation of Wet Web
The trend in papermaking has been towards lower basis weights, decreased amounts of softwood kraft pulp and an increased use of fillers and recycled fibers. All these changes tend to result in lower strengths of both wet and dry web. To maintain necessary strength in the papers, a greater quantity of strength additives is often required. The effect of different polymers on the dry paper strength has been widely studied and the action of mechanism of different polymers is quite well known. There is much less information of their effect on wet web properties, and especially on the tensile strength and relaxation characteristics. In this laboratory scale study, the effects of adding different polymers by spraying on wet web tensile and relaxation characteristics at high strain rate were examined. The sprayings were done on wet paper sheets before wet pressing. The results showed that spraying of polymers significantly improves wet and dry paper tensile strength without any increase in dry paper density. The effect of different polymers on wet web mechanical properties was characteristic for each polymer. Carboxymethyl cellulose (CMC) and chitosan improved wet web tensile strength at dryness levels higher than 55%, while polyvinyl alcohol (PVA) improved wet web tensile strength also at lower dryness levels. The most prominent increase in dry and wet web tensile strength was obtained by sequential application of oppositely charged polymers. However, the relative increase of tensile strength was significantly higher for the wet web (80% increase) than for the dry paper (35% increase) compared to the reference without added polymer. Also the mode of polymer addition had a significant effect on wet web tensile strength. Despite a significant increase in the wet web strength, only minor effects on the residual tension (tension after 0.475 s relaxation) was observed. Based on this result, it was concluded that spray addition of the polymers used in this study increased molecular level interactions between fibers but had no effect on the fiber network activation.