SOLIDIONIC

Yu.M.Baikov,  B.T.Melekh, V.A.Klimov, E.I.Nikulin, L.G.Baikova

Ioffe Physical Technical Institute of RAS, Saint-Petersburg,                                194021 Russian Federation,  baikov.solid@mail.ioffe.ru

Fig.1 Simple  model electrochemical cell.          The details: glass tube as a case; metallic Sn and graphite as electrodes; solid electrolyte obtained after cooling the melt of  61w % of KOH and 39 w %  H₂O.Lighting head of match for scaling.

Sn(-)|KOH·2H₂O| C(+)

The semiconductor-protonic heterojunction in the heterostructure ‘C(+)|KOH·2H₂O|Si(-)’ could be considered as the opportunity of the matching of small-sized electronic devices with batteries studied  here.

Compound compositions NaOH, KOH, H₂O of lower melting points showed high proton conductivity at 300-450 K^1,2. They are  eutectics KOH\KOH·H₂O (372.5K), KOH\NaOH(448K), and KOH·H₂O (419K) and  NaOH·H₂O (338K).

The pioneering investigation of the electrochemical activity of certain ionic heterostructures with solid electrolyte KOH·2H₂O (T_melt=315 K) is due to basic and applied interest in. The special study of different chemical elements of IV group (C, Si, Sn, Pb) as electrodes of electrochemical cells in contact with hydroxide superproton conductor as electrolyte has been performed.

Table 1.

EMF (1,2 – 1,3 V) and exchange currents (~0,1-1 mA/cm²) of  ‘C | KOH·2H₂O | TiFe’ and  ‘C | KOH·2H₂O | Sn’ are adequate to work as low-power sources for electronic devices. Therefore they could be factually batteries without any catalysts and noble metals, i.e. from cheap materials.

The metal-proton heterojunction Sn(-)|KOH·2H₂O has been studied firstly. It is characterized by exchange current at 290 K (1 mA/cm², a polish surface).

References

1. Yu.M.Baikov,SolidStateIonics 181 (2010) 545

2 Yu.M.Baikov, J.Power Sources 193 (2009) 371

The support of Programm of Presidium of RAS “Quantum Physics of Condensed Matter” .