Solid oxide electrochemical device with flat tube structure and preparation method thereof

Abstract

The invention relates to the field of electrochemistry, and discloses a solid oxide electrochemical device with a flat tube structure and a preparation method thereof. The electrochemical device comprises an external electrode, an external electrode connecting line, an electrolyte, an internal electrode, an internal electrode connecting line, and an isolation structure; the external electrode andthe external electrode connecting line are connected and arranged on the external side surface of the electrolyte, and the internal electrode and the internal electrode connecting line are connected and arranged at inner side of electrolyte; the isolation structure is composed of electrolyte, air passage walls at the two sides, and a separator plate which are encircled; and an air passage with openings at double ends is arranged in the isolation structure. The flat tube type electrochemical device has good sealing and high reliability; the device has yield and mass production is easy; at the same time, stacking is flexible, hot replacement operation of spent batteries under high temperature condition is supported, service life of SOC electric piles is substantially prolonged, operation elasticity is enhanced, and operation cost is reduced.

Description

technical field [0001] The invention relates to a solid oxide fuel cell, a solid oxide fuel electrolytic cell, new energy sources, new materials and the field of electrochemistry, in particular to a solid oxide electrochemical device with a flat tube structure and a preparation method thereof. Background technique [0002] SOC (solid oxide cells) is a solid oxide electrochemical device consisting of at least one layer of electrolyte and at least two electrodes. The electrolyte is usually doped stable zirconia, such as 8 mol% Y2O 3 Stabilized Zirconia (8YSZ) or Sc 2 o 3 Doped stabilized zirconia, such as ScSZ, or calcium oxide CaO stabilized zirconia (CSZ). The electrolyte can also be other fluorite-structured oxides, such as gadolinium oxide or samarium oxide-doped stable cerium oxide (GDC, SDC), or perovskite-structured oxides, such as LaSrGaMgO, etc. The material composition of the electrode can be an oxide with a perovskite structure, such as LaSrMnO 3 (LSM), it can a...

AI Technical Summary

Problems solved by technology

[0018] 1) The reliability of the sealing ring is not high

The sealing ring needs to ensure airtightness, heat cycle resistance, certain mechanical strength and flexibility, and must be close to the thermal expansion coefficient of the alloy connecting plate and the SOC cell (that is, thermal expansion matching, that is, the sealing ring is required to withstand temperature changes. conditions and the dimensional changes of the seal), whether it is glass or metal sealing rings, it is difficult to achieve these performance requirements at the same time

For example, the glass sealing ring is usually very fragile, and it is very easy to break and fail during the stacking and thermal cycle operation of the SOC

[0019] 2) Since each stacking component needs to be manufactured separately, the technical requirements are high (such as the flatness, strength, toughness, oxidation resistance, and thermal expansion matching of each component have high requirements), and the chip SOC stacking cost is usually higher , which also limits its practical application

[0020] 3) Low stacking flexibility

[0022] 1) Due to the cylindrical shape of the tubular SOC, it is difficult to achieve straightness in actual preparation, and it is difficult to ensure tightness between the electrode connection material and the cylindrical electrode, especially under high temperature conditions, which leads to the contact of a single battery. high resistance

[0023] 2) When the battery is manufactured, it is difficult for the various components of the single tubular battery to achieve consistent geometrical changes in the curved surface configuration (usually the shrinkage of the blank is consistent), which leads to the consistent geometrical dimensions of the tubular SOC single battery Poor performance, large residual stress in the battery, affecting the yield and stability of battery performance

The structure of the tubular battery with this intermediate passage design is complex, the seal between the electrolyte and the intermediate passage is difficult, and it is easy to leak air and cause battery failure.

[0025] 4) The structure of connecting the internal and external electrodes of each single battery to form a battery stack is complex. The current resistance of the entire tubular SOC battery stack is large, and the current density / power density is generally low

[0026] 5) Like a chip SOC stack, in a tubular SOC stack, if a single battery fails, because it is impossible to ensure good contact between the new battery and other batteries, and it is impossible to replace the faulty battery under high temperature conditions, the single battery The failure of the battery will lead to the degradation of the irreparable performance of the whole stack of batteries, and may even lead to the failure of the whole stack

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