CN102509783A - Microwave hydrothermal preparation method of positive electrode material LiV3O8 of lithium battery - Google Patents

Abstract

A microwave hydrothermal preparation method of a positive electrode material LiV3O8 of a lithium battery comprises the following steps of: dissolving LiOH.H2O and NH4VO3 into deionized water to obtain a solution A; adding DL-malic acid into the solution A to obtain a solution B; putting the solution B into an ultrasonic generator with the water temperature of 50-80 DEG C, performing ultrasonic treatment, and cooling to the room temperature to obtain a solution C; putting the solution C into a drying box and evaporating till no water exists to obtain a solid; grinding the solid and putting the ground solid into a crucible; thermally processing the solid in a muffle furnace, and cooling the solid in the muffle furnace to obtain the final product. By a microwave hydrothermal method, substances are more uniformly dispersed and the chemical synthesis can be facilitated; by the method, LiV3O8 microcrystals with few flaws, uniform chemical components, small particle size and uniform particle size distribution can be prepared; and the microwave hydrothermal preparation method is simple and environment-friendly, and has a low post treatment temperature and a short reaction period.

Description

A kind of anode material of lithium battery LiV 3O 8The using supersonic, water-heating preparation method

Technical field

The present invention relates to a kind of preparation method of lithium ion secondary battery anode material, be specifically related to a kind ofly combine hydro-thermal technology to prepare anode material of lithium battery LiV with ultrasonic wave ₃O ₈Method.

Background technology

Lithium rechargeable battery have voltage height, specific energy big, have extended cycle life, advantage such as discharge performance is stable, fail safe is good, pollution-free and operating temperature range is wide, therefore, obtained development rapidly in recent years, and had broad application prospects.As one of key technology of lithium rechargeable battery, the research and development of positive electrode are vital, and the raising of positive electrode chemical property is with the performance of improving lithium ion battery greatly.

Nineteen fifty-seven, Wadsley proposes lamellar compound LiV ₃O ₈Can be used as the positive electrode of lithium-ions battery.After this, Besenhard etc. discover, lamellar compound Li _1+xV ₃O ₈Not only have good embedding lithium ability, and have the specific capacity height, advantage such as have extended cycle life.In theory, the Li of 1mol _1+xV ₃O ₈Can embed the above Li of 3mol ⁺, this makes it have higher specific capacity, and generally more than 300mAh/g, the diffusion coefficient of lithium is 10 ^-12～10 ^-14m ²Between/the s, the higher therein chemical diffusion rate of lithium ion makes lithium when embedding and deviating from, and positive electrode has good Stability Analysis of Structures type, thereby has longer cycle life.Based on these characteristics, Li _1+xV ₃O ₈Obtain the extensive concern and the research of Chinese scholars in recent years, also become the anode material of lithium battery of one of tool development prospect in recent years.

Prepare Li at present _1+xV ₃O ₈The method of anode material of lithium battery mainly contains: solid phase method [Kawakita J, Kato T, Katayama Y, et al.Lithium insertion behavior of Li _1+xV ₃O ₈With different degrees of crystallinity [J] .J.Power Sources, 1999,81～82:448～453], sol-gal process [Li Liu; Lifang Jiao, Yanhui Zhang, Junli Sun; Lin Yang, et al.Synthesis of LiV ₃O ₈By an improved citric acid assisted sol-gel method at low temperature [J] .Materials Chemistry and Physics; 2008; 111:565～569], microwave sintering [Gang Yang; Guan Wang, and Wenhua Hou.Microwave Solid-State Synthesis of LiV ₃O ₈As Cathode Material for Lithium Batteries [J] .J.Phys.Chem.B; 2005; 109:11186～11196], spray pyrolysis [S.H.Ju, Y.C.Kang.Morphological and electrochemical properties of LiV ₃O ₈Cathode powders prepared by spray pyrolysis [J] .Electrochimica Acta; 2010,55:6088～6092], hydro thermal method [Hai Yan Xu, Hao Wang; Zhi Qiang Song, et al.Novel chemical method for synthesis of LiV ₃O ₈Nanords as cathode materials for lithium ion batteries [J] .Electrochimica Acta, 2004,49:349～353].These method process cycles long otherwise to experimental facilities have relatively high expectations, the prepared big and skewness of material particle size, it is bigger that performance differs.Because the preparation technology of anode material of lithium battery has very important influence to the performance of its material, then seeks suitable method and technology, the research and development of anode material of lithium battery there is significant meaning.

Summary of the invention

The object of the invention is to provide that a kind of preparation temperature is low, diameter of particle is even, and technological operation is simple, and can obtain the anode material of lithium battery LiV that particle diameter is little and be evenly distributed ₃O ₈The using supersonic, water-heating preparation method.

For achieving the above object, the technical scheme that the present invention adopts is:

1) press Li: V=1: 3 mol ratio is with analytically pure LiOHH ₂O and NH ₄VO ₃Be dissolved in the deionized water, be mixed with Li ⁺Concentration is the A solution of 0.02～0.15mol/L;

2) get DL-malic acid with metal ion species amount sum equivalent, and it slowly be dissolved in the A solution under the magnetic agitation, B solution;

3) B solution being placed on water temperature is in 50～80 ℃ the supersonic generator, under agitation carries out ultrasonic Treatment, and ultrasonic power is 400W～800W, and ultrasonic time is 1～3 hour;

4) sonicated intact after, be cooled to room temperature, using ammoniacal liquor to regulate its pH value is 4～8 to obtain C solution;

5) C solution is placed on evaporating water gets solid in 60～120 ℃ the electric drying oven with forced convection;

6) solid is placed in the crucible after levigate, places Muffle furnace to obtain end product with the stove cooling after 6～10 hours again in 300～500 ℃ of following heat treatments.

The present invention adopts ultrasonic wave to combine the method for hydro-thermal, ultrasonic wave can make more even that material disperses, and promotes the carrying out of chemical reaction, in this way, can prepare that defective is few, chemical composition is even, the little and LiV that is evenly distributed of particle diameter ₃O ₈Crystallite, this preparation technology is simple, and is environmentally friendly, the post-processed temperature is low, reaction time is short.

Description of drawings

Fig. 1 is the embodiment of the invention 3 prepared LiV ₃O ₈The X-ray diffraction of positive electrode (XRD) collection of illustrative plates.

Fig. 2 is the embodiment of the invention 3 prepared LiV ₃O ₈The field emission scanning electron microscope of positive electrode (FESEM) photo.

Embodiment

Below in conjunction with accompanying drawing and embodiment the present invention is done further explain.

Embodiment 1:

1) press Li: V=1: 3 mol ratio is with analytically pure LiOHH ₂O and NH ₄VO ₃Be dissolved in the deionized water, be mixed with Li ⁺Concentration is the A solution of 0.02mol/L;

2) get DL-malic acid with metal ion species amount sum equivalent, and it slowly be dissolved in the A solution under the magnetic agitation, B solution;

3) B solution being placed on water temperature is in 50 ℃ the supersonic generator, under agitation carries out ultrasonic Treatment, and ultrasonic power is 700W, and ultrasonic time is 1 hour;

4) sonicated intact after, be cooled to room temperature, using ammoniacal liquor to regulate its pH value is 5 to obtain C solution;

5) C solution is placed on evaporating water gets solid in 60 ℃ the electric drying oven with forced convection;

6) solid is placed in the crucible after levigate, places Muffle furnace to obtain end product with the stove cooling after 8 hours again in 400 ℃ of following heat treatments.

Embodiment 2:

1) press Li: V=1: 3 mol ratio is with analytically pure LiOHH ₂O and NH ₄VO ₃Be dissolved in the deionized water, be mixed with Li ⁺Concentration is the A solution of 0.10mol/L;

2) get DL-malic acid with metal ion species amount sum equivalent, and it slowly be dissolved in the A solution under the magnetic agitation, B solution;

3) B solution being placed on water temperature is in 60 ℃ the supersonic generator, under agitation carries out ultrasonic Treatment, and ultrasonic power is 600W, and ultrasonic time is 2 hours;

4) sonicated intact after, be cooled to room temperature, using ammoniacal liquor to regulate its pH value is 4 to obtain C solution;

5) C solution is placed on evaporating water gets solid in 100 ℃ the electric drying oven with forced convection;

6) solid is placed in the crucible after levigate, places Muffle furnace to obtain end product with the stove cooling after 6 hours again in 500 ℃ of following heat treatments.

Embodiment 3:

1) press Li: V=1: 3 mol ratio is with analytically pure LiOHH ₂O and NH ₄VO ₃Be dissolved in the deionized water, be mixed with Li ⁺Concentration is the A solution of 0.05mol/L;

2) get DL-malic acid with metal ion species amount sum equivalent, and it slowly be dissolved in the A solution under the magnetic agitation, B solution;

3) B solution being placed on water temperature is in 80 ℃ the supersonic generator, under agitation carries out ultrasonic Treatment, and ultrasonic power is 800W, and ultrasonic time is 3 hours;

4) sonicated intact after, be cooled to room temperature, using ammoniacal liquor to regulate its pH value is 6.8 to obtain C solution;

5) C solution is placed on evaporating water gets solid in 80 ℃ the electric drying oven with forced convection;

6) solid is placed in the crucible after levigate, places Muffle furnace to obtain end product with the stove cooling after 10 hours again in 300 ℃ of following heat treatments.

The powder of gained is carried out thing with Japanese D/max2000PC x-ray diffractometer of science characterize (Fig. 1) mutually, its XRD diffracting spectrum and LiV ₃O ₈Standard card is perfect corresponding, explains that products therefrom is the LiV of pure phase ₃O ₈This product is observed (Fig. 2) with NEC's strain formula meeting (JEOL) JSM-6460 type scanning electron microscopy, can draw prepared LiV from picture ₃O ₈The crystallite pattern is corynebacterium, and its particle size is about 100～300nm.

Embodiment 4:

1) press Li: V=1: 3 mol ratio is with analytically pure LiOHH ₂O and NH ₄VO ₃Be dissolved in the deionized water, be mixed with Li ⁺Concentration is the A solution of 0.15mol/L;

2) get DL-malic acid with metal ion species amount sum equivalent, and it slowly be dissolved in the A solution under the magnetic agitation, B solution;

3) B solution being placed on water temperature is in 70 ℃ the supersonic generator, under agitation carries out ultrasonic Treatment, and ultrasonic power is 400W, and ultrasonic time is 3 hours;

4) sonicated intact after, be cooled to room temperature, using ammoniacal liquor to regulate its pH value is 7 to obtain C solution;

5) C solution is placed on evaporating water gets solid in 120 ℃ the electric drying oven with forced convection;

6) solid is placed in the crucible after levigate, places Muffle furnace to obtain end product with the stove cooling after 9 hours again in 350 ℃ of following heat treatments.

Embodiment 5:

1) press Li: V=1: 3 mol ratio is with analytically pure LiOHH ₂O and NH ₄VO ₃Be dissolved in the deionized water, be mixed with Li ⁺Concentration is the A solution of 0.12mol/L;

2) get DL-malic acid with metal ion species amount sum equivalent, and it slowly be dissolved in the A solution under the magnetic agitation, B solution;

3) B solution being placed on water temperature is in 65 ℃ the supersonic generator, under agitation carries out ultrasonic Treatment, and ultrasonic power is 500W, and ultrasonic time is 2 hours;

4) sonicated intact after, be cooled to room temperature, using ammoniacal liquor to regulate its pH value is 8 to obtain C solution;

5) C solution is placed on evaporating water gets solid in 90 ℃ the electric drying oven with forced convection;

6) solid is placed in the crucible after levigate, places Muffle furnace to obtain end product with the stove cooling after 7 hours again in 450 ℃ of following heat treatments.

Claims (1)

1. anode material of lithium battery LiV ₃O ₈The using supersonic, water-heating preparation method, it is characterized in that:

1) press Li: V=1: 3 mol ratio is with analytically pure LiOHH ₂O and NH ₄VO ₃Be dissolved in the deionized water, be mixed with Li ⁺Concentration is the A solution of 0.02～0.15mol/L;

2) get DL-malic acid with metal ion species amount sum equivalent, and it slowly be dissolved in the A solution under the magnetic agitation, B solution;

3) B solution being placed on water temperature is in 50～80 ℃ the supersonic generator, under agitation carries out ultrasonic Treatment, and ultrasonic power is 400W～800W, and ultrasonic time is 1～3 hour;

4) sonicated intact after, be cooled to room temperature, using ammoniacal liquor to regulate its pH value is 4～8 to obtain C solution;

5) C solution is placed on evaporating water gets solid in 60～120 ℃ the electric drying oven with forced convection;

6) solid is placed in the crucible after levigate, places Muffle furnace to obtain end product with the stove cooling after 6～10 hours again in 300～500 ℃ of following heat treatments.

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