CN102263289A - Application of porphyrin as catalyser in Li/SOCI2 (Lithium Thionyl Chloride) battery - Google Patents

Abstract

The invention discloses an application of porphyrin as a catalyser in a Li/SOCI2 battery. Porphyrin and phthalocyanine are high-conjugacy compounds containing macrocycles and have similar catalytic performance. In thionyl chloride electrolytic solution, the solubility of porphyrin is higher than that of phthalocyanine due to the influence of solvent polarity, therefore more porphyrins are facilitated to take part in catalytic reaction of batteries, and electron transfer in the reaction of the batteries is facilitated. Zn (TPP) (Zinc Tetraphenylporphyrin) is used as a catalyser to catalyze Li/SOCI2 battery, the open-circuit voltage, the battery capacity and the average voltage of the battery can be effectively increased. The solubility of a porphyrin composition in SOCI2 electrolytic solution is larger than that of a phthalocyanine composition, therefore, more metal porphyrins is facilitated to take part in the electron transfer reaction of batteries.

Description

Porphyrin as catalyst at Li/SOCl＜sub 2＜/sub application and battery in the battery

Technical field

The present invention relates to porphyrin as catalyst at Li/SOCl ₂Application in the battery and battery belong to technical field of electrochemistry, especially Li/SOCl ₂The battery technology field.

Background technology

Lithium/thinly chloride battery is the higher disposable battery of a kind of specific energy, militarily has a wide range of applications.The open circuit voltage of lithium/thinly chloride battery can reach 3.65V, and operating voltage is generally about 3.3V, and simultaneously, it also has long, characteristics such as storage life is long, cryogenic property good, negative voltage is steady discharge time.Macrocyclic complex with conjugated structure (for example: phthalocyanine), join in the battery electrolyte, can effectively reduce the internal resistance of battery, help the raising of battery open circuit voltage and the prolongation of discharge time.At present, this technology also is in conceptual phase, the mechanism of improving about the phthalocyanines complex also is not very clear, people such as P.A.Bernstein have studied the electron transport mechanism of cobalt phthalocyanine (CoPc) in battery, in the entire cell course of reaction, phthalocyanine adds the electron transfer that helps cell reaction, has reduced the activation energy of entire reaction, and CoPc can circular regeneration, has suppressed SOCl simultaneously ₂With the reaction of Li electrode, make amount that LiCl generates seldom, the internal resistance of cell is effectively reduced.

In the catalyst research about thionyl chloride battery, everybody focuses on the phthalocyanines complex, yet there are no report but porphyrin is used for thionyl chloride battery as catalyst.

Summary of the invention

Technical problem to be solved by this invention provides a kind of Li/SOCl ₂The new catalyst of battery and battery thereof, adopt following technical scheme:

Porphyrin as catalyst at Li/SOCl ₂Application in the battery.

Described application, wherein, described porphyrin is Zn (TPP).

Described application, wherein, the consumption of described Zn (TPP) is: add catalyst ZnTPP 2～2.5mg in every electrolyte.

A kind of Li/SOCl also is provided ₂Battery, this Li/SOCl ₂Battery uses porphyrin as catalyst, and described porphyrin is Zn (TPP).

Porphyrin and phthalocyanine all are the high conjugacy compounds that contains big ring, catalytic performance is close, in thionyl chloride electrolyte, because the influence of solution polarity, the dissolubility of porphyrin is higher than phthalocyanine, help like this going in the catalytic reaction that more porphyrin participates in battery, help the transfer of electronics in the cell reaction.

Use Zn (TPP) as catalyst Li/SOCl ₂Battery can effectively improve open circuit voltage, battery capacity and the average voltage of battery.Porphyrin class complex is at SOCl ₂Solubility in the electrolyte is big than the phthalocyanines complex, therefore, more helps the electron transfer reaction that more metalloporphyrin participates in battery.

Description of drawings

Fig. 1 is the synthetic route of Zn (TPP);

Fig. 2 is the infrared spectrum of Zn (TPP);

Fig. 3 is the ultraviolet-visible light spectrogram of Zn (TPP);

Fig. 4 is the Li/SOCl of Zn (TPP) catalysis ₂The battery discharge curve;

Fig. 5 is the graph of a relation of discharge average voltage and Zn (TPP);

The graph of a relation of Fig. 6 battery capacity and Zn (TPP).

Embodiment

Below in conjunction with specific embodiment, the present invention is described in detail.

Embodiment 1

1.1 tetraphenyl zinc protoporphyrin (Zn (TPP)) is synthetic

Synthesize and be divided into for two steps (building-up process is seen Fig. 1), the first step, at first synthetic tetraphenylporphyrin, adopt ripe Alder propionic acid method, the concrete operations step is: add the 300mL propionic acid in the 500mL three-necked bottle, again 6.08mL (60mmol) dissolution of benzaldehyde is added reactor in the 15mL propionic acid, stir, and be heated to the propionic acid backflow, in 15min, in reactor, add the propionic acid solution that 10mL is dissolved with 4.16mL (60mmoL) pyrroles then.Solution becomes brownish black, continues lucifuge reaction 1h, removes the heating electromagnetic oven, leaves standstill cooling, all propionic acid of pressure reducing and steaming, and evaporate to dryness adds 200mL ethanol, standing over night in refrigerator in reactor as far as possible.Next day decompress filter, and with ice ethanol cyclic washing suction filtration product, colourless to filtrate, dry 10h in the vacuum drying chamber obtains the purple pressed powder.The crude product that obtains is dissolved with carrene, is that eluent, chromatographic silica gel are that immobile phase carries out column chromatography with carrene and alcohol mixed solvent, collects first colour band, is product.

Synthetic Zn (TPP) of second step, concrete operations are: add the CHCl that 30mL is dissolved with 50mg (0.081mmol) tetraphenylporphyrin in round-bottomed flask ₃Solution is again to wherein adding excessive zinc acetate dihydrate solid 0.22g (1mmol)).Stir 24h under the room temperature, and monitor with TLC, treat porphyrin and slaine complete reaction, stop reaction, filter unreacted zinc acetate, washed reaction liquid is used anhydrous Na SO ₄Dried overnight.Filtering, after the solvent evaporated, is eluent with carrene and n-hexane mixed solution, and 80-100 order chromatographic silica gel is that immobile phase carries out column chromatography, collects the mass-tone band and is product.

1.2Zn structural characterization (TPP)

With C, H, the N constituent content in elemental analyser (Vario EL-III) (Germany) the test complex, (UV1800, shimadzu) uv-vis spectra of (Daojin International Trade (Shanghai) Co., Ltd.) test porphyrin is used WRS-1 with ultraviolet-visual spectrometer _ANumeral fusing point instrument (Shanghai Physics Optics Instrument Factory) is tested its fusing point, with the infrared spectrum of infrared spectrometer (Bruker BEQ UZNDX550-FTIR, KBr compressing tablet) (Germany) KBr compressing tablet test complex.

1.3Zn fusing point (TPP), infrared spectrum and uv-vis spectra

Zn (TPP) is done series characterize, characterization data sees Table 1.From table data as can be seen, Zn (TPP) results of elemental analyses and theoretical value are approaching, Fig. 2 is the infrared spectrogram of Zn (TPP), Fig. 3 is the ultraviolet-visible light spectrogram, it is consistent that its characteristic peak and porphyrins feature go out the peak, shows that Zn (TPP) synthesizes.

Table 1Zn (TPP) characterization data

Embodiment 2

2.1Zn (TPP) be used for the lithium/thinly chloride battery performance test

Zn (TPP) is used for Li/SOCl as catalyst ₂Battery, test add before and after the catalyst, the discharge curve of battery.Concrete test condition is: guarantee assemble in the dry air environment of relative humidity＜1%, negative pole is the metal lithium bands of light, carbon-point just very, and (add catalyst ZnTPP 2～2.5mg) in every milliliter of electrolyte is 1.47mol/L LiAlCl to electrolyte ₄/ SOCl ₂, separate with the PP film between the both positive and negative polarity.Under nitrogen protection, metalloporphyrin complex Zn (TPP) (2-2.5mg) is added in the 1mL electrolyte of battery, simultaneously, it is uniformly dispersed in electrolyte.The battery testing condition is: 23～25 ℃ of ambient temperatures, permanent resistance 40 Ω, average current density 70mA/cm ², continuous discharge to voltage falls to 2V, respectively the output voltage and the time relation of test battery.

2.2Zn (TPP) to Li/SOCl ₂The influence of battery performance

Li/SOCl ₂The battery discharge curve is seen Fig. 4, compares with blank, and behind the adding Zn (TPP), obviously prolonged the discharge time of battery, and simultaneously, the open circuit voltage of battery is compared also with blank and is significantly improved.

In order to further specify Zn (TPP) to the thionyl chloride battery Effect on Performance, cell voltage data among Fig. 4 are carried out analytical calculation, quantize Zn (TPP) to Li/SOCl ₂The average voltage of battery and the influence of battery capacity.The following computing formula of main application in the analytic process:

Average voltage: U _Av=∑ U Δ t/ ∑ Δ t (1)

Battery capacity: $C=\∫\mathrm{Pdt}=\∫\frac{U^2}{R_e}\mathrm{dt}---\left(2\right)$

R wherein _e=40 Ω write down a secondary data every 30s

Therefore, the computing formula of battery capacity can be reduced to:

$C=\mathrm{\&Sigma;}\frac{U^2}{R_e}\mathrm{\&Delta;t}=\frac{1}{R_e}\mathrm{\&Sigma;}{\mathrm{<figure-callout\; id="2"\; label="U"\; filenames="DEST\_PATH\_HSB00000577091000011.png"\; state="\{\{state\}\}">U</figure-callout>}}^2\mathrm{\&Delta;t}=\frac{1}{40}\mathrm{\&Sigma;}{\mathrm{<figure-callout\; id="2"\; label="U"\; filenames="DEST\_PATH\_HSB00000577091000011.png"\; state="\{\{state\}\}">U</figure-callout>}}^2\mathrm{\&Delta;t}---\left(3\right)$

According to above formula, battery data to Zn (TPP) catalysis calculates, obtain table 2, Zn (TPP) data are done block diagram and Capacity Plan analysis (seeing Fig. 5 and Fig. 6), after clearly showing adding Zn (TPP) porphyrin, the average voltage of battery and battery capacity all have rising in various degree, average voltage has improved 3.27%, battery capacity has improved 24.5%, this may be because Zn (TPP) porphyrin can quicken the electron transfer in the battery, stop the formation of LiCl film, therefore can effectively improve the performance of battery.

Table 2Zn (TPP) catalysis thionyl chloride battery data analysis table

3, conclusion

Use Zn (TPP) as catalyst Li/SOCl ₂Battery can effectively improve open circuit voltage, battery capacity and the average voltage of battery.Porphyrin class complex is at SOCl ₂Solubility in the electrolyte is big than the phthalocyanines complex, therefore, more helps the electron transfer reaction that more metalloporphyrin participates in battery.

Should be understood that, for those of ordinary skills, can be improved according to the above description or conversion, and all these improvement and conversion all should belong to the protection range of claims of the present invention.

Claims (3)

1. Porphyrin as catalyst at Li/SOCl ₂Application in the battery, described porphyrin are Zn (TPP).
2. 2. application according to claim 1 is characterized in that, the consumption of described Zn (TPP) is: every milliliter of SOCl ₂Add catalyst ZnTPP 2～2.5mg in the electrolyte.
3. 3. Li/SOCl ₂Battery is characterized in that, uses porphyrin as catalyst, and described porphyrin is Zn (TPP).

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