Conducting Solids In the Search for Multivalent Cation Transport

Conducting Solids In the Search for Multivalent Cation Transport 

Irrespective of these controversies, research in this intriguing area is crucially important from both fundamental and applied points of view. For instance, solid electrolytes and mixed conductors with mobile AP + cations may find applications in new types of rechargeable battery, and also in the aluminum industry alkaline-earth cation conductors may be used, in particular, for precise humidity control in gaseous media and for CO2 sequestration. This chapter includes a brief introduction to the field, with emphasis placed primarily on the authors own studies. Although many aspects of materials electrochemical behavior require detailed investigation and further validation, the chapter provides an excellent overview of the phases where multivalent cation conduction may occur. 

P-Alumina (general composition Naj +xAlii0i7 4, /2) has a layered structure with a conducting NaO plane sandwiched between AIuOk, blocks the lattices of P -alumina (general composition Naj + xM vAl M divalent cations such as Mg) also 

Na and Nd with increasing temperature, and that the ion-exchanged Nd -P -alumina was not a pure trivalent Nd cationic conductor, but rather a Na and Nd mixed ionic conductor at elevated temperatures. The existence of other ion-exchanged Ln -P -aluminas has also been in doubt, notably with regards to whether Ln is the only migrating cationic species, or not, and for the same reason as considered for Nd -P -alumina. 

Trivalent ion-exchange reactions for polycrystalline Na -P -alumina have rarely been reported (e.g., for Na /Nd -P -alumina [38]), mainly because ion exchange into Na -P -alumina polycrystals is much more difficult than for a single crystalline material, especially in the case of trivalent cations. However, no electrical conductivity measurements were conducted on these samples. 

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I S Conducting Solids In the Search for Multivalent Cation Transport SC2(WO4)3... 

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