MnO2-RuO2/C catalyst for lithium-air battery and preparation method of MnO2-RuO2/C catalyst

Abstract

The invention discloses a MnO2-RuO2 / C catalyst for a lithium-air battery and a preparation method of the MnO2-RuO2 / C catalyst. An active substance of the catalyst is MnO2-RuO2, a carrier of the catalyst is nanocarbon, and MnO2-RuO2 and nanocarbon comprise the following components by weight percent: 5-20 percent of MnO2, 25-55 percent of nanocarbon and the balance being RuO2. The nanocarbon is coated with nano MnO2-RuO2, and a great quantity of nano MnO2 and RuO2 particles are adsorbed by taking the nanocarbon as a carrier in the process of preparing the catalyst, so that the surface of the carrier is stably coated with MnO2 and RuO2, and the stability and the activity of the catalyst are improved. Meanwhile, because the nanocarbon is coated, the contact between the nanocarbon and Li2O2 is reduced, side reactions are reduced, and energy efficiency and cycle performance of the battery are improved.

Description

technical field

[0001] The invention relates to the technical field of lithium-air batteries, in particular to MnO for lithium-air batteries 2 -RuO 2 / C catalyst and its preparation method. Background technique

[0002] As a new type of high-efficiency green and environmentally friendly energy, lithium-air batteries have ultra-high specific capacity, energy density as high as 11140wh / kg, reversibility, environmental friendliness, and low cost. Among them, carbon materials are the most important positive electrode materials, but when carbon materials are used as the main positive electrode materials, there are mainly the following two problems.

[0003] First of all, the overvoltage is high, mainly due to the high overvoltage of the oxygen evolution reaction in the discharge process, while RuO 2 It is a good efficient catalyst for oxygen evolution reaction, but its catalytic activity for redox reaction is low; MnO 2 It is a better oxygen reduction catalyst, but the cataly...

Examples

Embodiment 1

[0023] Dissolve 0.82g potassium permanganate in 24ml deionized water, and dissolve 0.37g manganese sulfate in 10ml deionized water. Potassium permanganate solution was added dropwise to manganese sulfate solution, fully stirred evenly, hydrothermally reacted in a reaction kettle at 160°C for 12h, filtered and washed 6 times, and dried at 100°C for 12h. Take 0.0545gRuCl 3 ·ⅹH 2 O, 0.1g multi-walled carbon nanotubes, 0.05g MnO 2 Dissolve in deionized water, ultrasonically disperse for 0.5h, put the mixed solution in a reaction kettle, react with water at 180°C for 12h, filter with suction, wash with deionized water and ethanol three times respectively, and dry at 100°C for 8h to obtain MnO 2 -RuO 2 Coated multi-walled carbon nanotube catalysts.

Embodiment 2

[0025] Dissolve 0.82g of potassium permanganate in 24ml of deionized water, and dissolve 0.37g of manganese sulfate in 10ml of deionized water. Potassium permanganate solution was added dropwise to manganese sulfate solution, fully stirred evenly, hydrothermally reacted in a reaction kettle at 160°C for 12h, filtered and washed 6 times, and dried at 100°C for 12h. Take 0.05gRuCl 3 ·ⅹH 2 O, 0.1gSuperP, 0.05gMnO 2 Dissolve in deionized water, ultrasonically disperse for 0.5h, put the mixed solution into a reaction kettle, react with water at 180°C for 12h, filter with suction, wash with deionized water and ethanol three times respectively, and dry at 110°C for 8h to obtain MnO 2 -RuO 2 Coated SuperP catalyst.

Embodiment 3

[0027] Dissolve 0.8g of potassium permanganate in 24ml of deionized water, and 0.4g of manganese sulfate in 10ml of deionized water. Potassium permanganate solution was added dropwise to manganese sulfate solution, fully stirred evenly, hydrothermally reacted in a reaction kettle at 160°C for 12h, filtered and washed 6 times, and dried at 100°C for 12h. Take 0.05gRuCl 3 ·ⅹH 2 O, 0.1g graphene, 0.05g MnO 2 Dissolve in deionized water, ultrasonically disperse for 0.5h, put the mixed solution into a reaction kettle, react with water at 180°C for 12h, filter with suction, wash with deionized water and ethanol three times respectively, and dry at 100°C for 10h to obtain MnO 2 -RuO 2 Catalysts coated with graphene.

technical field

[0001] The invention relates to the technical field of lithium-air batteries, in particular to MnO for lithium-air batteries 2 -RuO 2 / C catalyst and its preparation method. Background technique

[0002] As a new type of high-efficiency green and environmentally friendly energy, lithium-air batteries have ultra-high specific capacity, energy density as high as 11140wh / kg, reversibility, environmental friendliness, and low cost. Among them, carbon materials are the most important positive electrode materials, but when carbon materials are used as the main positive electrode materials, there are mainly the following two problems.

[0003] First of all, the overvoltage is high, mainly due to the high overvoltage of the oxygen evolution reaction in the discharge process, while RuO 2 It is a good efficient catalyst for oxygen evolution reaction, but its catalytic activity for redox reaction is low; MnO 2 It is a better oxygen reduction catalyst, but the cataly...

Examples

Embodiment 1

[0023] Dissolve 0.82g potassium permanganate in 24ml deionized water, and dissolve 0.37g manganese sulfate in 10ml deionized water. Potassium permanganate solution was added dropwise to manganese sulfate solution, fully stirred evenly, hydrothermally reacted in a reaction kettle at 160°C for 12h, filtered and washed 6 times, and dried at 100°C for 12h. Take 0.0545gRuCl 3 ·ⅹH 2 O, 0.1g multi-walled carbon nanotubes, 0.05g MnO 2 Dissolve in deionized water, ultrasonically disperse for 0.5h, put the mixed solution in a reaction kettle, react with water at 180°C for 12h, filter with suction, wash with deionized water and ethanol three times respectively, and dry at 100°C for 8h to obtain MnO 2 -RuO 2 Coated multi-walled carbon nanotube catalysts.

Embodiment 2

[0025] Dissolve 0.82g of potassium permanganate in 24ml of deionized water, and dissolve 0.37g of manganese sulfate in 10ml of deionized water. Potassium permanganate solution was added dropwise to manganese sulfate solution, fully stirred evenly, hydrothermally reacted in a reaction kettle at 160°C for 12h, filtered and washed 6 times, and dried at 100°C for 12h. Take 0.05gRuCl 3 ·ⅹH 2 O, 0.1gSuperP, 0.05gMnO 2 Dissolve in deionized water, ultrasonically disperse for 0.5h, put the mixed solution into a reaction kettle, react with water at 180°C for 12h, filter with suction, wash with deionized water and ethanol three times respectively, and dry at 110°C for 8h to obtain MnO 2 -RuO 2 Coated SuperP catalyst.

Embodiment 3

[0027] Dissolve 0.8g of potassium permanganate in 24ml of deionized water, and 0.4g of manganese sulfate in 10ml of deionized water. Potassium permanganate solution was added dropwise to manganese sulfate solution, fully stirred evenly, hydrothermally reacted in a reaction kettle at 160°C for 12h, filtered and washed 6 times, and dried at 100°C for 12h. Take 0.05gRuCl 3 ·ⅹH 2 O, 0.1g graphene, 0.05g MnO 2 Dissolve in deionized water, ultrasonically disperse for 0.5h, put the mixed solution into a reaction kettle, react with water at 180°C for 12h, filter with suction, wash with deionized water and ethanol three times respectively, and dry at 100°C for 10h to obtain MnO 2 -RuO 2 Catalysts coated with graphene.