Method for compositely coating lithium battery positive electrode material with tungsten oxide and nitrogen-doped carbon

Abstract

The invention belongs to the technical field of manufacturing of lithium battery cathode materials, and specifically relates to a method for compositely coating a lithium battery cathode material withtungsten oxide and nitrogen-doped carbon. A coating layer is formed on the surface of the lithium battery positive electrode material by polymerization of a carbon precursor and precipitation of a tungsten precursor. Curing and bonding of coating layer are realized through a calcining process. According to the present invention, the method has characteristics of low cost, low energy consumption and simple operation, and the lithium battery positive electrode material prepared through the method has characteristics of excellent electronic conductivity and excellent electrochemical stability.

Description

technical field

[0001] The invention belongs to the technical field of lithium battery anode material production, and in particular relates to a method for composite coating lithium battery anode materials with tungsten oxide and nitrogen-doped carbon. Background technique

[0002] Lithium iron phosphate is one of the most widely used lithium battery electrode materials. This is mainly due to the good cycle stability brought about by the olivine crystal structure of lithium iron phosphate. On the other hand, lithium iron phosphate does not contain expensive and environmentally polluting components such as cobalt, so it has obvious advantages in material preparation and waste treatment (Chem. Eng. J. 2020, 379, 122371). However, lithium iron phosphate also has many inherent problems, which mainly include the weak electronic conductivity of lithium iron phosphate and the poor rate performance of lithium iron phosphate caused by the slow lithium ion transport performance (Ener...

Examples

Embodiment 1

[0028] Dissolve ammonium metatungstate in 19 mL of water, and then disperse 1.9 grams of lithium iron phosphate in the ammonium metatungstate solution; dissolve dopamine in 1 mL of deionized water, and add it to the solution containing lithium iron phosphate and ammonium metatungstate In the dispersion, a mixed reaction solution was prepared, wherein the amount of the ammonium metatungstate substance in the mixed reaction solution was 0.024mmol, and the amount of the dopamine substance was 1.26mmol;

[0029] The mixed reaction solution was stirred at 25°C for 24 hours, and the obtained product was centrifuged, washed, and dried to obtain a tungsten and carbon precursor co-coated lithium iron phosphate material;

[0030] The dry tungsten and carbon precursor co-coated lithium iron phosphate positive electrode material was calcined under argon protection and the calcination temperature was 500°C for 6 hours to obtain the tungsten oxide and nitrogen-doped carbon co-coated lithium ...

Embodiment 2

[0038]Dissolve ammonium paratungstate in 19 mL of water, then disperse 1.9 grams of lithium iron phosphate in the ammonium paratungstate solution; dissolve dopamine in 1 mL of deionized water, and add it to the dispersion containing lithium iron phosphate and ammonium paratungstate to prepare a mixed reaction solution , wherein, the amount of the ammonium paratungstate substance in the mixed reaction solution is 0.01mmol, and the amount of the dopamine substance is 0.44mmol;

[0039] The mixed reaction solution was stirred at 5°C for 5 hours, and the obtained product was centrifuged, washed, and dried to obtain a tungsten and carbon precursor co-coated lithium iron phosphate material;

[0040] The dry tungsten and carbon precursor co-coated lithium iron phosphate cathode material was calcined under argon protection and the calcination temperature was 300°C for 7 hours to obtain the tungsten oxide and nitrogen-doped carbon co-coated lithium iron phosphate cathode material;

[0...

Embodiment 3

[0043] Dissolve sodium phosphotungstate in 19 mL of water, then disperse 1.9 g of lithium iron phosphate in the sodium phosphotungstate solution; dissolve dopamine in 1 mL of deionized water, and add it to the solution containing lithium iron phosphate and sodium phosphotungstate In the dispersion, a mixed reaction solution is obtained, wherein the amount of the ammonium paratungstate substance in the mixed reaction solution is 0.01mmol, and the amount of the dopamine substance is 0.55mmol;

[0044] The mixed reaction solution was stirred at 68°C for 30 hours, and the obtained product was centrifuged, washed, and dried to obtain a tungsten and carbon precursor co-coated lithium iron phosphate material;

[0045] The dry tungsten and carbon precursor co-coated lithium iron phosphate positive electrode material was calcined under argon protection and the calcination temperature was 420°C for 18 hours to obtain the tungsten oxide and nitrogen-doped carbon co-coated lithium iron pho...

technical field

[0001] The invention belongs to the technical field of lithium battery anode material production, and in particular relates to a method for composite coating lithium battery anode materials with tungsten oxide and nitrogen-doped carbon. Background technique

[0002] Lithium iron phosphate is one of the most widely used lithium battery electrode materials. This is mainly due to the good cycle stability brought about by the olivine crystal structure of lithium iron phosphate. On the other hand, lithium iron phosphate does not contain expensive and environmentally polluting components such as cobalt, so it has obvious advantages in material preparation and waste treatment (Chem. Eng. J. 2020, 379, 122371). However, lithium iron phosphate also has many inherent problems, which mainly include the weak electronic conductivity of lithium iron phosphate and the poor rate performance of lithium iron phosphate caused by the slow lithium ion transport performance (Ener...

Examples

Embodiment 1

[0028] Dissolve ammonium metatungstate in 19 mL of water, and then disperse 1.9 grams of lithium iron phosphate in the ammonium metatungstate solution; dissolve dopamine in 1 mL of deionized water, and add it to the solution containing lithium iron phosphate and ammonium metatungstate In the dispersion, a mixed reaction solution was prepared, wherein the amount of the ammonium metatungstate substance in the mixed reaction solution was 0.024mmol, and the amount of the dopamine substance was 1.26mmol;

[0029] The mixed reaction solution was stirred at 25°C for 24 hours, and the obtained product was centrifuged, washed, and dried to obtain a tungsten and carbon precursor co-coated lithium iron phosphate material;

[0030] The dry tungsten and carbon precursor co-coated lithium iron phosphate positive electrode material was calcined under argon protection and the calcination temperature was 500°C for 6 hours to obtain the tungsten oxide and nitrogen-doped carbon co-coated lithium ...

Embodiment 2

[0038]Dissolve ammonium paratungstate in 19 mL of water, then disperse 1.9 grams of lithium iron phosphate in the ammonium paratungstate solution; dissolve dopamine in 1 mL of deionized water, and add it to the dispersion containing lithium iron phosphate and ammonium paratungstate to prepare a mixed reaction solution , wherein, the amount of the ammonium paratungstate substance in the mixed reaction solution is 0.01mmol, and the amount of the dopamine substance is 0.44mmol;

[0039] The mixed reaction solution was stirred at 5°C for 5 hours, and the obtained product was centrifuged, washed, and dried to obtain a tungsten and carbon precursor co-coated lithium iron phosphate material;

[0040] The dry tungsten and carbon precursor co-coated lithium iron phosphate cathode material was calcined under argon protection and the calcination temperature was 300°C for 7 hours to obtain the tungsten oxide and nitrogen-doped carbon co-coated lithium iron phosphate cathode material;

[0...

Embodiment 3

[0043] Dissolve sodium phosphotungstate in 19 mL of water, then disperse 1.9 g of lithium iron phosphate in the sodium phosphotungstate solution; dissolve dopamine in 1 mL of deionized water, and add it to the solution containing lithium iron phosphate and sodium phosphotungstate In the dispersion, a mixed reaction solution is obtained, wherein the amount of the ammonium paratungstate substance in the mixed reaction solution is 0.01mmol, and the amount of the dopamine substance is 0.55mmol;

[0044] The mixed reaction solution was stirred at 68°C for 30 hours, and the obtained product was centrifuged, washed, and dried to obtain a tungsten and carbon precursor co-coated lithium iron phosphate material;

[0045] The dry tungsten and carbon precursor co-coated lithium iron phosphate positive electrode material was calcined under argon protection and the calcination temperature was 420°C for 18 hours to obtain the tungsten oxide and nitrogen-doped carbon co-coated lithium iron pho...

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