Spin coating preparation method for dense diffusion barrier layer of limiting current type oxygen sensor

Abstract

The invention discloses a spin coating preparation method for a dense diffusion barrier layer of a limiting current type oxygen sensor, and belongs to the technical field of chemical gas sensors. The method comprises the following steps: dissolving a binder in a solvent, forming an organic carrier, and uniformly dispersing LSM in the organic carrier, thus preparing LSM of dense diffusion barrier layer slurry, wherein the mass ratio of LSM to the solvent to the binder is equal to (2- 6) : (5-10) : (0.01-0.05); spinning at 1000 to 10000r / min for 1 to 10min by a spin-coating instrument, coating the dense diffusion barrier layer slurry on the surface of YSZ uniformly, then drying to obtain a solid electrolyte which has a layer of the dense diffusion barrier layer on the dried surface; sintering for 5 to 7h at the temperature of 1000 to 1600 DEG C, thus preparing the dense diffusion barrier layer of the limiting current type oxygen sensor coated on the solid electrolyte. The dense diffusion barrier layer prepared by the method is dense and uniform in structure, compact and pore-free, high in bonding strength with a substrate, precisely controllable in thickness and short in manufacturing cycle.

Description

technical field [0001] The invention relates to the technical field of chemical gas sensors, in particular to a method for preparing a dense diffusion barrier layer of a limiting current type oxygen sensor by spin coating. Background technique [0002] In industries such as automobiles, metallurgy, and energy, it is an effective method to use electrochemical sensors to monitor oxygen concentration online and in real time. According to different working principles, electrochemical sensors can be divided into two types: concentration battery type and limiting current type. In comparison, the limiting current type makes up for the shortcomings of the concentration battery type, such as slow response and low sensitivity to the lean combustion zone. Short response time, high sensitivity, long life, no need for reference gas, etc. The limiting current type oxygen sensor is divided into small hole type, porous type and dense diffusion barrier layer type. Among them, the small hole...

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Problems solved by technology

Since LSM is easily reduced by C in the SPS sintering process, the thermal expansion coefficient mismatch between LSCM and YSZ causes cracking of the sintered body, so the oxygen measurement performance is not ideal

Liu Tao et al took Sr 1-x Y x CoO 3-δ is a dense diffusion barrier layer, with La 0.8 Sr 0.2 Ga 0.83 Mg 0.17 o 2.815 (LSGM) is a solid electrolyte, and the oxygen sensor is prepared by the ceramic chip composite method, which has good oxygen measurement characteristics. However, the preparation process of this method is cumbersome and the cycle is long, and the dense diffusion barrier layer prepared by the conventional sintering method contains many pores.

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