CN108808047A - LSCF/Na2CO3Nanocomposite is the preparation method of fuel cell ion transport layer - Google Patents

Abstract

The invention discloses a kind of LSCF/Na₂CO₃Nanocomposite is the preparation method of fuel cell ion transport layer, and step is：By LSCF/Na₂CO₃5%~40% Na of total amount₂CO₃It is dissolved in the aqueous solution that water forms a concentration of 0.5mol/L；LSCF/Na will be accounted for₂CO₃The LSCF of total weight 60%~95% is added to Na₂CO₃In solution, using magnetic stirrer 15min, make two kinds of full and uniform mixing of material；Compound is put into electric drying oven with forced convection in 120 DEG C of dry 12h；The calcining 1h, as LSCF/Na at 700 DEG C will be put in Muffle furnace after compound grinding 15min after drying₂CO₃Nanocomposite.It is that the fuel cell that ion transport layers are assembled into shows good power output using the composite material.Material preparation method of the present invention is simple to operation, and material sintering temperature is relatively low.Material cost and material preparation are at low cost, the easy compression moulding of composite material.

Description

LSCF/Na2CO3Nanocomposite is the preparation method of fuel cell ion transport layer

Technical field：

The invention belongs to field of solid oxide fuel, utilize La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ(LSCF) /Na₂CO₃ Composite material builds fuel cell as ion transport layers, and to Na in composite material₂CO₃Amount be optimized.

Background technology：

Solid oxide fuel cell (solid oxide fuel cell, SOFC) is that a kind of chemical energy by hydrogen is straight Switch through all solid state electrochemical generating unit for turning to electric energy, there is energy conversion efficiency high (up to 50%~80%), noiseless The advantages that small with environmental pollution.Traditional fuel cell structure includes three components：Cathode, anode, electrolyte.Wherein electrolyte It is the core component of the device, it can determine the type, operation temperature and final energy conversion efficiency of device.What yttrium was stablized Zirconium oxide (YSZ) is used as most successful electrolyte, has ruled the development of SOFC more than 100 years, not only has high ion Conductivity and good electrode matching have superior chemical stability also under hydrogen-oxygen atmosphere.But in order to make electrolyte YSZ Sufficiently high oxygen ionic conductivity (0.1S/cm) is obtained, battery needs work at a high temperature of 1000 DEG C, and hot operation is easy to lead Send a telegraph pole sintering, interface diffusion occurs for electrolyte and electrode and thermally expands and mismatches, cause material selection range is narrow, between interface The problems such as mechanical stress is excessive, battery life reduces.Operation temperature is dropped into 600 DEG C of middle low-temperature spaces below, it not only can be effective Battery life is improved, and raw material and production cost can also be reduced.

(500-800 DEG C) electrolyte with high ionic conductivity under middle low temperature is prepared and developed, and is answered It is an effective way for realizing low temperature in SOFC to use in fuel cell.It can be substantially by two-phase or three-phase Material cladding Degree improves the ionic conductivity of material, reduces its activation energy.Most typically doped cerium oxide-carbonate composite material, the material Material has preferably chemistry, thermal matching and mechanical strength compared with single-phase electrolyte, while also possessing higher ion Electric conductivity.Wang et al. is reported in Ce_0.8Sm_0.2O_1.9(SDC)/Na₂CO₃In composite material [Wang.XD, Ma.Y, Raza.R, Muhammed. M, Zhu.B.Electrochemistry Communications 10 (2008) 1617-1620], unformed shape Na₂CO₃It is wrapped on SDC particles and forms nucleocapsid, which is that a kind of superionic conductors (is higher than 300 in temperature DEG C when, ionic conductivity be more than 0.1S/cm), and using this material be electrolyte assembling SOFC, obtained under 550 DEG C of test temperatures Obtain 0.8W/cm²Excellent properties.Xie et al. is research shows that La_0.9Sr_0.1Ga_0.8Mg_0.2O_2.85(LSGM) -52mol%Li₂CO₃: 48mol%Na₂CO₃Carbonate composite material has 0.122Scm at 600 DEG C in air^-1High ionic conductivity, than pure LSGM Conductivity wants height [Xie.FC, Wang.C, Mao.ZQ, Zhan.ZL.International Journal of Hydrogen Energy 38(2013)11085-11089]。

The present invention uses for reference carbonate complex method to prepare La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ(LSCF)/Na₂CO₃Novel electrolytic Material, and build SOFC by ion transport layers of this material.

Invention content:

The purpose of the present invention is develop the LSCF/Na with high ionic conductivity under middle low temperature₂CO₃Novel carbonate is multiple Condensation material, and applied in solid oxide fuel cell as ion transport layers, it is intended to battery operational temperatures are reduced, are carried High battery performance.

The LSCF/Na of the present invention₂CO₃New Type of Carbon silicate composite material preparation process is as follows：

1, LSCF/Na will be accounted for₂CO₃The Na of total amount 5%₂CO₃It being added in 20ml deionized waters, stirring makes it completely dissolved, Form the aqueous sodium carbonate of a concentration of 0.5mol/L；

2, LSCF/Na will be accounted for₂CO₃The LSCF of total weight 95% is added to Na₂CO₃In solution, magnetic stirrer is utilized 15min makes two kinds of full and uniform mixing of material；

LSCF is bought in U.S.'s Sigma Aldriches；

3, the compound after being sufficiently mixed is put into electric drying oven with forced convection in 120 DEG C of dry 12h；

4, it by after the compound grinding 15min after drying, is put in Muffle furnace and calcines 1h at 700 DEG C to get 5%Na₂CO₃ The LSCF/Na of content₂CO₃Composite material；

5, step 1-4 is repeated, different Na are prepared₂CO₃The LSCF/Na of content (10%, 20%, 30%, 40%)₂CO₃It is multiple Condensation material.

Fuel cell manufacturing process：

1. prepared by battery：

(a) the NCAL powder of 2g is added in the terpinol of 5mL, grinding 10min makes the full and uniform mixing of the two, prepares NCAL slurries.The slurry prepared is coated in the nickel foam that thickness is 2mm, then 120 DEG C of dry 1h in drying box, is completed The preparation of Ni-NCAL electrodes.

Ni_0.8Co_0.15Al_0.05LiO_δ(NCAL) purchase rubs joint high-tech company in Tianjin treasured.

(b) LSCF/Na after 0.35g is fully ground is weighed₂CO₃Compound, Ni-NCAL layers, LSCF/Na₂CO₃It is compound Powder, Ni-NCAL layer are sequentially placed into mold, apply 9MPa pressure using hydraulic press, three-decker is pressed into battery base Piece.

2. battery testing：The blank suppressed is put into test furnace, 30min is sintered at 550 DEG C.After the completion of sintering At a temperature of 550 DEG C, H₂Flow is that 120ml/min is tested, and battery shows good power output.

The advantage of the present invention：

(1) material preparation method of the present invention is simple to operation, and material sintering temperature is relatively low.Material cost and material preparation at This low, easy compression moulding of composite material.

(2) cell manufacturing process of the present invention is simple and practicable, and cell manufacturing process is compared with conventional batteries without high temperature sintering work Sequence.

(3) it is tested at a temperature of 550 DEG C, battery shows good power output.Battery has higher in middle low-temperature space Power output, the operation temperature of SOFC is successfully reduced to 600 degree or less.

Description of the drawings

Fig. 1 is to utilize different Na₂CO₃The LSCF/Na of content₂CO₃Composite material forms fuel cell, the property at 550 DEG C It can test result.

As shown, battery performance is with Na₂CO₃The beginning that increases of content is gradually increasing, and then reduces again.When Na₂CO₃When content is 10%, battery peak power output reaches extreme value, power 700mW/cm².Work as Na₂CO₃Content is 5% When, battery open circuit voltage (OCV) drastically declines, this is because excessive LSCF, it is logical to form electric network transmission in inside battery Road causes electrical short so that OCV is reduced.

Fig. 2 is LSCF/Na prepared by the present invention₂CO₃The conductivity of (10wt%) composite material.

As shown, with the raising of temperature, the conductivity of composite material gradually rises.In addition when temperature be more than 450 DEG C, Conductivity is obviously aggravated with the raised rate of temperature, and there are one apparent chatterings.The phenomenon and doping reported in the literature Cerium oxide/carbonate composite material is similar, is primarily due to when temperature is more than 450 DEG C, Na₂CO₃Molten condition is initially located in, The Na of molten state₂CO₃LSCF particle exterior surfaces can be wrapped in, channel is provided for the transmission of carrier, its conductivity is made drastically to increase Greatly；For the material at 600 DEG C, ionic conductivity reaches 0.2946S/cm.

Fig. 3 is by 10Na₂CO₃- 90LSCF composite materials are assembled into the SEM sectional views of battery.

The battery has apparent three-decker, and both sides are the foam nickel electrode for being symmetrically coated with NCAL, two electrode layers Thickness is all 800 μm.Centre is LSCF/Na₂CO₃Composite material functional layer, thickness are 500 μm.

Specific implementation mode

Embodiment 1

(1) 1g Na are weighed₂CO₃Powder is dissolved in a certain amount of deionized water, forms the sodium carbonate of 0.5mol/L Aqueous solution；

(2) 9g LSCF powder is weighed, Na is added it to₂CO₃In solution, 15 min of magnetic stirrer is used in combination, makes LSCF and Na₂CO₃Solution is uniformly mixed, and is then put it into drying box in 120 DEG C of dry 12h；

(3) by the mortar grinder 15min of the mixture after drying, 700 DEG C of calcining 1h of Muffle furnace are put into；

(4) by the LSCF/Na after calcining₂CO₃Composite material is fully ground again.Weigh 0.35g LSCF/Na₂CO₃It is compound Material does battery functi on layer, is clipped in two panels Ni-NCAL electrode layers, forms sandwich structure, ceramics are pressed into using hydraulic press Piece battery, pressure size 9MPa；

(5) battery is mounted on test fixture, is put into after test furnace calcine 30min at 550 DEG C, progress battery performance survey Examination, H when test₂Flow is 120ml/min.

Embodiment 2

Na is made with reference to embodiment 1₂CO₃The ceramic cell piece that content is 5%, 20%, 30%, 40%.Test result is shown in figure 1。

Claims (2)

1. a kind of LSCF/Na₂CO₃Nanocomposite is the preparation method of fuel cell ion transport layer, it is characterised in that step For：

1) LSCF/Na will be accounted for₂CO₃The Na of total amount 5%~40%₂CO₃It is added in 20ml deionized waters, stirring keeps it completely molten Solution, forms the aqueous sodium carbonate of a concentration of 0.5mol/L；

2) LSCF/Na will be accounted for₂CO₃The LSCF of total weight 60%~95% is added to Na₂CO₃In solution, stirred using magnetic stirring apparatus 15min is mixed, two kinds of full and uniform mixing of material are made；

3) compound after being sufficiently mixed is put into electric drying oven with forced convection in 120 DEG C of dry 12h；

4) the calcining 1h at 700 DEG C will be put in Muffle furnace after the compound grinding grinding 15min after drying；

5) step 1-4 is repeated, different Na are prepared₂CO₃The Na of content₂CO₃/ LSCF composite materials (5%, 10%, 20%, 30%, 40%).

2. according to a kind of LSCF/Na₂CO₃Nanocomposite is the preparation method of fuel cell ion transport layer, it is characterised in that Step is：

1) LSCF/Na will be accounted for₂CO₃The Na of total amount 10%₂CO₃It is added in 20ml deionized waters, stirring makes it completely dissolved, and is formed 0.5mol/L aqueous sodium carbonates；

2) LSCF/Na will be accounted for₂CO₃The LSCF of total amount 90% is added to Na₂CO₃In solution, using magnetic stirrer 15min, Make two kinds of full and uniform mixing of material；

3) compound after being sufficiently mixed is put into electric drying oven with forced convection in 120 DEG C of dry 12h；

4) compound after drying is ground into 15min, is put in Muffle furnace the calcining 1h at 700 DEG C；As prepare Na₂CO₃Content is 10% Na₂CO₃/ LSCF composite materials.