SOLIDIONIC

1.   Solid Hydroxide Eutectics as Self-Organized Nanostructured Electrolytes for Small-Sized and Low- Power Electrochemical Devices at Intermediate Temperatures Range

Yu.M. Baikov, B.T.Melekh, V.A.Klimov, V.M.Egorov
Ioffe Physico-Technical Institute, St Petersburg, Russia

Nanostructured eutectics (NaOH+KOH),(KOH+KOH.H2O), (LiOH+NaOH),  (KNH2+NaNH2) have sufficiently more higher ionic (protonic) conductivity than their  “parent” individual compounds. Studying such phenomena is useful for physics of nano-materials as well as for promising technological application for synthesis and using for energy storage and conversion.

Full article available here
Solid Hydroxide Eutectics as Self-Organized Nanostructured

2.  Little-known catalytic and electrochemical activity of solid alkaline hydroxides for energy conversion and storage

Yu.M. Baikov,  E.I. Nikulin,  B.T. Melekh,  M.E.Kompan
Ioffe Physical Tekhnical Institute, Solid State Physics,Polytekhnicheskaja 26, St-Petersburg 194021

The effectiveness of chemical reactions used for energy conversion and storage is due to opportunity  of    ‘participants’    to  activate  mutually  or  one  by  one,  e.g.  the  activation  of dihydrogen as fuel by metallic electrodes. However, the crucial role, as a rules, play  catalytic agents or electric field, particularly to finding new arrangements of processes and devices for energy conversion and storage. Recently new (or little known) combinations of electrolytes and electrodes were found and presented in our papers [1-3]. The main part of them are different forms of solid ALKALINE [4] hydroxides.

Full article available here
Little-known catalytic and electrochemical activity of solid alkaline hydroxides for energy conversion and storage

 3. Chemical effect on spin-electron subsystem of transition metal oxides

Yurii M. Baikov*, B.T.Melekh, E.I.Nikulin
Ioffe Physical Technical Institute, St. Petersburg, Russia

Now one can say not only on the influence of spin subsystem on chemical properties , but also on possible chemical modification of spin subsystem. In this sense, the most effective way   is controlled   changing   of   the   number   of   electrons   by   mild   chemical   reactions.   Such physico-chemical modification is presented for somewhat different, chemically modified oxides of transition metal, namely, YBa2Cu3O7, LaMn1-x(Ca/Sr)xO3, CexSr1-xMnO3, as initial compounds.

Full article available here
Chemical effect on spin-electron subsystem of transition metal oxides

• Heads of European and St-Petersburg groups part1
• Slovenia SSPC9 Truls N. and Yurii B. already agree part2
•  1998 SSPC9 Slovenia Search Collaboration (KDKreuer and Yurii) part2a
• 2000 SSPC10 Mon-Pelie and SSI 7 Corsica (Grand Blue) part 3
• 2000 INTAS 99-0636 1st meeting May StPetersburg part 4
• 2001 European Meeting on Protonics March Gol Norway part 5
• 2001 INTAS 99-0636 3rd meeting October Russia (Ural) part6
• 2002 INTAS 99-0636 4th meeting London-Guilford at SSPC11 part 7a
• 2002 Almost whole INTAS 99-0636 in Guilford part 7b
• 2002 East Horsley (UK) Home of Ruth and Brain Steele part 8
• 2002 European SSI 9 Rhodes (Greece) part 8
• 2003 INTAS 99-0636 6th Final meeting Almaty part 10
• 2003 INTAS 99-0636 ALMATY in Laboratory and in Theater part11
• 2003 INTAS 99-0636 Almaty Norby FWP Igor Vladislav part 12
• 2003 Int.Forum on Magnet. Rome 2003 Hydrogen in GMR part 9
• 2004 INTAS 99-0636 SSPC 12 Упсала (Sweden)
• 2001 INTAS 00-0728 URAL Hydrogen effect on Perovskite Oxides

Dear Colleagues!

Please consider and discuss below presented сomplete quasichemical description of some cubic oxides similar YO1.5 and double perovskites in water and oxygen atmosphere

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I would like to propose for starters to divide the set of subjects onto two groups according to remarks in “Introduction” about preferably my personal interest (items ”a” and “b”) and evidently common interest (items “c” and “d”). Of course such division has enough relative character, but, by my opinion, it seems suitable.

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

The family of complex materials such as crystalline hydrates and solid eutectics, on the base of hydroxides of alkaline metals (Na, K, Rb, Cs) has been studied thoroughly from the general physico-chemical point of view. However, the high proton conductivity of the members of this family has been revealed on for the last few years. Correspondingly there was no information on the electrochemical activity of heterostructures “alkaline proton | electron conductor”. In our opinion the crucial reason for this objectionable approach of world ionic community to whole alkaline-hydroxide-family was due to dramatic history of arising and then falling of interest in individual alkaline hydroxides. The key aim of the paper is to present our results of the development of solid and molten hydroxide materials which are good proton conductors at intermediate / room temperatures (450 < T < 250K) and low-humidity or even anhydrous conditions, as well as are electrochemically active in MEA with Ti, TiFe, Sn and Si. The main experimental results and informal discussions on necessary further progress in fundamental understanding of the underlying proton conduction mechanisms are collected now on website http://www.solidionic.com.

Authors : Yu. M. Baikov, E. I. Nikulin, B. T. Melekh, V. A. Klimov

“Old” isotopic methods, namely both isotopic exchange (IsEx) and isotopic effect(IsEff), are the effective characterization technique at the study of interface and surface processes at different length scales. Factually, they are in-situ techniques of significant importance at the study of mass and charge transport across and along interfaces of recently discovered ionic conductors on the base of alkaline hydroxides, namely crystalline KOH·H2O (Tmelt=146°C) and KOH·2H2O (Tmelt=42°C) as individual compounds and solid eutectic NaOH+KOH (ENaK) (Tmelt=185°C). See http://www.solidionic.com. The isotopic technique supplied to traditional physico- and electrochemical techniques is factually phenomenological modelling for a deeper understanding of the underlying transport and reactivity mechanisms. We present the results of the study of IsEff (H<=>D) of both the conductivity and EMF of the heterojunction electrode|protonics as well as IsEx “gas-electrolyte” and “electrode-electrolyte”. The rate of IsEx “gas(H2)-a.m.electrolytes” was compared with the exchange-current on the interface “TiHx(or PdHy)| a.m.electrolytes”. The main conclusions are following. i)The mobility of hydrogen species is higher along internal interfaces than across them in the microheterogenic ENaK. ii) The reality of hydrogen heterojunction has been confirmed. iii) The surface of hydroxides itself can activate the molecular hydrogen.

Comparison of electrochemical cells with different isotoppic conten in electrolyte

 C(grahite)|KOH·2H2O|Sn

Isotopic effect of voltammetry

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” .

Abstract—The self-diffusion coefficients of ions of the three chemical elements forming lithium hydroxide have been determined by the crystal–crystal and crystal–gas isotope exchange method in the temperature range 500–720 K. Crystal samples with different isotope compositions have been grown by the Bridgman method from melts. The melting temperature is 743 ± 2 K. Original methods have been developed for high-precision measurements of the isotope ratios of all the three elements, i.e., lithium (⁶Li/⁷Li), hydrogen (H/D), and oxygen (¹⁶O/¹⁸O), and their changes after diffusion annealing with the use of the same sample. The self-diffusion coefficients of lithium and hydrogen ions differ but by a factor of no more than 3–5; however, their magnitudes exceeds those for oxygen by several orders of magnitude. In particular, at 670 K, they are equal to 6.0·10^-9 , 3.2·10^–9, and 2.0·10^–12 cm² s^–1 for hydrogen, lithium, and oxygen, respectively. In the range 680–720 K, the self-diffusion coefficients of hydrogen and lithium increase sharply with increasing temperature to approximately 10^–6 cm² s^–1. A probable mechanism of migration of protons and lithium ions in LiOH and the role played in this process by the oxygen ions with a lower mobility have been discussed.

DOI: 10.1134/S1063783410100070

Correction of   the equation  (5) in

Self-Diffusion of Lithium, Hydrogen, and Oxygen Ions in Crystalline Lithium Hydroxide  2010 Vol. 52,  No.10, 2044-2057 (the correction elated to third member in (5) on P.2054)

Исправление  формулы (5) в статье

ФТТ 2010  Том 52 вып 10  на стр 1917

Full article in English is here

Self of Lithium, Hydrogen, and Oxygen Ions in Crystalline Lithium Hydroxide.PDF

Full article in Russian is here

Самодиффузия ионов лития, водорода и кислорода в кристаллическом гидроксиде лития.PDF