Cathode material used for lithium sulfur battery, preparation and application thereof

A cathode material, lithium-sulfur battery technology, applied in battery electrodes, circuits, electrical components, etc., can solve the problems of sulfur electrochemical inertness and poor cycle stability, reduced battery charge and discharge efficiency, and low electrode capacity utilization, etc. The effect of cycle stability, good selectivity, good catalytic activity

Active Publication Date: 2016-02-10
DALIAN INST OF CHEM PHYSICS CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] However, its practical application is limited due to the electrochemical inertness and poor cycle stability of sulfur.
The reduction of elemental sulfur to lithium sulfide is a multi-step reaction such as Figure 4 Shown, S 8 Restore to go through S 6 - , S 4 - , S 2 - , S 2- Intermediate state, from S 8 Direct conversion to lithium sulfide reaction has a higher energy barrier and the reaction is more difficult
Moreover, the intermediate product of the electrochemical reaction with sulfur is easily soluble in the electrolyte, causing a large loss of active substances, reducing the electrode capacity, increasing the viscosity of the electrolyte, decreasing the ion conductivity, and deteriorating the electrode performance.
The "Shuttle" effect of soluble polysulfides leads to a decrease in battery charge and discharge efficiency and low electrode capacity utilization, while insoluble lithium sulfide deposits and agglomerates on the electrode surface, destroying the electrode structure and reducing the cycle performance of the battery

Method used

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  • Cathode material used for lithium sulfur battery, preparation and application thereof
  • Cathode material used for lithium sulfur battery, preparation and application thereof
  • Cathode material used for lithium sulfur battery, preparation and application thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0039] Take 0.83ml of ammonium molybdate aqueous solution with a concentration of 133.6mgMo / ml, add appropriate amount of water and isopropanol and ultrasonically mix it evenly (the mass percentage of ammonium molybdate is 5%), add conductive carbon Ketjen black, Ketjen black The mass percentage is 50%, stirred for half an hour to mix evenly, and soaked for 12 hours. The above mixture was slowly evaporated on a water bath at 90°C until the surface was dry, and then dried in a vacuum oven at 120°C for 2 hours; then the sample was moved into a tube furnace for sintering and nitriding. The roasting condition is N 2 In the atmosphere, the temperature was raised to 500°C at a constant temperature of 5°C / min for 2 hours, and then lowered to room temperature. Then pass 60ml / min of NH 3 Raise the temperature from room temperature to 623K at 5K / min; then raise the temperature from 623K to 723K at a speed of 0.5K / min, then raise the temperature from 723K to 973K at 2.5K / min, keep the ...

Embodiment 2

[0044] Take 0.25ml of ammonium metatungstate aqueous solution with a concentration of 441.216mgW / ml, add appropriate amount of water and isopropanol and ultrasonically mix it evenly (ammonium metatungstate mass percentage is 60%), add carbon nanotubes, carbon nanotubes The mass percentage is 10%, stirred for half an hour to mix evenly, and soaked for 12 hours. The above mixture was slowly evaporated on a water bath at 90°C until the surface was dry, and then dried in a vacuum oven at 120°C for 12 hours; then the sample was moved into a tube furnace for sintering and nitriding. The roasting condition is N 2 In the atmosphere, the temperature was raised to 500°C at a constant temperature of 5°C / min for 2 hours, and then lowered to room temperature. Then pass 60ml / min of NH 3 Raise the temperature from room temperature to 623K at 5K / min; then raise the temperature from 623K to 723K at a speed of 0.5K / min, then raise the temperature from 723K to 1025K at 2.5K / min, keep the tempe...

Embodiment 3

[0046] The precursor oxide of supported cobalt molybdenum nitride is impregnated: 0.59ml of Co(NO with a concentration of 134.4mgCo / ml 3 ) 2 ·6H 2 O aqueous solution was slowly added to 0.96ml of ammonium molybdate aqueous solution with a concentration of 133.6mgMo / ml, and the mixed solution was immersed in 0.5g of carbon nanofibers, stirred for half an hour to mix evenly, and then immersed for 12 hours. The above mixture was slowly evaporated on a water bath at 90°C until the surface was dry, and then dried in a vacuum oven at 120°C for 12 hours; then the sample was moved into a tube furnace for sintering and nitriding. The roasting condition is N 2 In the atmosphere, the temperature was raised to 500°C at a constant temperature of 5°C / min for 2 hours, and then lowered to room temperature. Then pass 60ml / min of NH 3 Raise the temperature from room temperature to 623K at 10K / min; then raise the temperature from 623K to 723K at a speed of 0.5K / min, then raise the temperatur...

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Abstract

The invention relates to a cathode material used for a lithium sulfur battery, preparation and an application thereof. The cathode material employs one or more than two carbides or nitrides of metal elements from transition metal as a catalytic component and employs elementary sulfur as an active component. The catalytic component is supported on a carrier firstly and then the active component is supported on the carrier on which the catalytic component is supported. The content of the catalytic component is 2-30% of the total weight of the cathode material and the content of the sulfur is 30-80% of total weight of the cathode material, and the balanced is the carrier. The cathode material, when being used as a cathode in the lithium sulfur battery, has excellent selectivity on reduction of elementary sulfur and reduces reaction energy barrier required for sulfur reduction, reduces reaction polarization and increases discharge voltage platform. The cathode material is environment-friendly, is low in cost and is abundant in resources.

Description

technical field [0001] The invention relates to a positive pole of a lithium-sulfur battery, in particular to a positive pole material and its preparation and application. Background technique [0002] In recent years, with the continuous advancement of science and technology and the rapid development of various electronic products, the chemical power sources used are required to have the characteristics of light weight, small size, and large capacity. In order to meet the needs of society and greatly increase the energy density of batteries, the development of new materials and new systems is necessary. [0003] The lithium-sulfur secondary lithium battery is one of the battery systems with a relatively high theoretical discharge capacity among known lithium-ion batteries. Among the cathode materials for batteries, elemental sulfur is abundant, cheap and environmentally friendly. The density of elemental sulfur is 1.96g / cm 3 , with a theoretical specific capacity of 1675...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/90H01M4/58
CPCY02E60/10Y02E60/50
Inventor 王美日张华民张洪章马艺文
Owner DALIAN INST OF CHEM PHYSICS CHINESE ACAD OF SCI
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