CN103474641A

CN103474641A - Lithium ion battery anode material Li3VO4 and preparation method thereof

Info

Publication number: CN103474641A
Application number: CN2013104409465A
Authority: CN
Inventors: 倪世兵; 吕小虎; 杨学林
Original assignee: China Three Gorges University CTGU
Current assignee: China Three Gorges University CTGU
Priority date: 2013-09-25
Filing date: 2013-09-25
Publication date: 2013-12-25

Abstract

The invention provides a Li3VO4 cathode anode material and a preparation method thereof, particularly a novel lithium ion battery anode material Li3VO4 prapared by carrying out hydrothermal reaction on vanadium pentoxide, lithium carbonate and hexamethylenetetramine used as precursors. The hydrothermal reaction is utilized to prepare an intermediate phase product, and the intermediate phase product is gradually subjected to solid-phase reaction while reaction energy is supplied by high temperature heating, thereby finally obtaining the Li3VO4 with favorable crystallinity. The first charge and discharge capacities of the Li3VO4 are respectively 523 and 423 mAh/g, and the charge and discharge capacities after 100 loops are still 398 mAh/g; and the grain size is uniform, and is less than 200nm.

Description

A kind of lithium ion battery negative material Li 3vO 4and preparation method thereof

Technical field

The present invention relates to a kind of Novel cathode material for lithium ion battery, particularly a kind of Li ₃vO ₄preparation method and storage lithium characteristic thereof, belong to field of electrochemical power source.

Background technology

Lithium ion battery is the third generation small battery after nickel-cadmium cell, Ni-MH battery, there is the advantages such as operating voltage is high, specific energy large, the discharge potential curve is steady, self discharge is little, have extended cycle life, cryogenic property is good, memoryless, pollution-free, can meet portable type electronic product miniaturization, lightweight, free of contamination requirement.Lithium ion battery not only is widely used in the electronic products such as mobile communication equipment, notebook computer, is also the ideal source of following electric vehicle as electric automobile and electric bicycle.In addition, lithium ion battery also has potential using value in the mobile devices such as artificial satellite, field operations communication the inside.The research direction of following lithium ion battery is further to improve specific energy and the specific power of battery, and the key of research and development high-energy-density, high power lithium ion cell is to design and prepare the electrode material of high power capacity, high rate capability.At present, positive electrode is generally containing lithium transition group metallic oxide (LiCoO ₂, LiFePO ₄, LiN _1-y-zmn _yco _zo _zdeng), the characteristics of existing positive electrode are that charge and discharge potential is higher, cycle performance is more stable, but specific capacity is on the low side.The possibility that increases substantially the positive electrode specific capacity on the existing structure basis is little, further improves the significantly raising that capacity of lithium ion battery can only rely on the negative material capacity.Traditional graphite cathode material theoretical capacity is lower, and density is lower, and volume and capacity ratio is low, researches and develops the key factor that novel high-volume and capacity ratio lithium ion battery negative material becomes leading lithium ion battery development.Ternary lithium, vfanadium compound system have shown good chemical property as lithium ion battery electrode material, thereby have been subject to studying comparatively widely and paying close attention to.And Li ₃vO ₄electrochemical Properties as lithium ion battery electrode material there is not yet report.Based on above research background, this patent relates to a kind of novel tertiary compound L i for preparing of invention ₃vO ₄the new method of material, using that it has shown excellent stable circulation performance as lithium ion battery negative.

Summary of the invention

The object of the present invention is to provide a kind of Li ₃vO ₄negative material and preparation method thereof, be specially and take vanadic oxide, lithium carbonate and hexamethylenetetramine as precursor, by hydro-thermal reaction, through heat treatment, prepares Novel cathode material for lithium ion battery Li ₃vO ₄.Its principle utilizes hydro-thermal reaction to prepare middle phase product exactly, then utilizes high-temperature heating that reaction energy is provided, and in the middle of making, solid phase reaction occurs the phase product gradually, finally obtains the Li that crystal property is good ₃vO ₄.

Li involved in the present invention ₃vO ₄synthesis material is vanadic oxide, lithium carbonate and hexamethylenetetramine.In the material preparation process, first lithium carbonate, vanadic oxide and hexamethylenetetramine are added to appropriate distilled water and stir to take according to mol ratio 3:1:2 ~ 10, to be positioned in beaker, then be positioned in hydrothermal reaction kettle in 120 ℃ of reactions 10 ~ 30 hours.The intermediate product that reaction is obtained is dried in baking oven, and under air 400 ~ 700 ℃ of lower sintering 1 ~ 10 hour, the naturally cooling Li that obtains ₃vO ₄sample.This material is graininess, and average-size is less than 200nm.

Li involved in the present invention ₃vO ₄negative material and preparation method have following outstanding feature:

(1) Li ₃vO ₄first the charge and discharge capacity be respectively 523,423mAh/g, after 100 circulations, the charge and discharge capacity is 398 mAh/g;

(2) synthesis technique is simple, easy operating, and the material preparation cost is low;

(3) the gained sample purity is high, and crystal property is good;

(4) prepared sample size is even, all is less than 200nm;

(5) prepared material cycle performance excellence.

the accompanying drawing explanation:

The prepared Li of Fig. 1 embodiment 1 ₃vO ₄the XRD collection of illustrative plates;

The SEM figure of Fig. 2 embodiment 1;

The discharge curve first (a) of Fig. 3 embodiment 1 and cycle performance figure (b).

embodiment:

Embodiment 1

First lithium carbonate, vanadic oxide are taken with mol ratio 3:1, then take the hexamethylenetetramine of 5 moles, add excessive distilled water after mixing and stir, be transferred in 120 ℃ of hydro-thermal axes reaction 24 hours, will react products therefrom and be transferred in culture dish and dry.To dry product and be positioned in crucible or quartz boat, and crucible or quartz boat are moved in high temperature process furnances, at 500 ℃, under air conditions, calcining is 5 hours, naturally coolingly can obtain Li ₃vO ₄sample.Result shows, as shown in Figure 1, prepared sample is pure Li through the XRD atlas analysis ₃vO ₄, corresponding to XRD card JCPDS, No. 38-1247, lattice constant is a=0.6319 nm, b=0.5448 nm, c=0.4940 nm; Be positioned at 16.3 ^o, 21.6 ^o, 22.9 ^o, 24.4 ^o, 28.2 ^o, 32.8 ^o, 36.3 ^o, 37.6 ^o, 42.7 ^o, 49.8 ^o, 58.7 ^o, 66.2 ^owith 70.9 ^odiffraction maximum correspond respectively to Li ₃vO ₄(100), (110), (011), (101), (111), (200), (002), (201), (112), (202), (320), (203) and (322) crystal face.Through sem analysis, as seen from Figure 2, prepared Li ₃vO ₄for the particle of size uniform, the particle average grain diameter is 200 nm.With prepared Li ₃vO ₄particle shows that as lithium ion battery negative material the charge and discharge capacity is 463,650 mAh/g first, and after 100 circulations, the charge and discharge capacity is respectively 402,402 mAh/g, has shown fabulous stable circulation performance, as shown in Figure 3.

Embodiment 2

First lithium carbonate, vanadic oxide are taken with mol ratio 2:1, then take the hexamethylenetetramine of 2 moles, add excessive distilled water after mixing and stir, be transferred in 120 ℃ of hydro-thermal axes reaction 30 hours, will react products therefrom and be transferred in culture dish and dry.To dry product and be positioned in crucible or quartz boat, and crucible or quartz boat are moved in high temperature process furnances, at 400 ℃, under air conditions, calcining is 8 hours, naturally coolingly can obtain Li ₃vO ₄sample.

Embodiment 3

First lithium carbonate, vanadic oxide are taken with mol ratio 5:1, then take the hexamethylenetetramine of 9 moles, add excessive distilled water after mixing and stir, be transferred in 120 ℃ of hydro-thermal axes reaction 12 hours, will react products therefrom and be transferred in culture dish and dry.To dry product and be positioned in crucible or quartz boat, and crucible or quartz boat are moved in high temperature process furnances, at 700 ℃, under air conditions, calcining is 2 hours, naturally coolingly can obtain Li ₃vO ₄sample.

Embodiment 4

First lithium carbonate, vanadic oxide are taken with mol ratio 5:1, then take the hexamethylenetetramine of 8 moles, add excessive distilled water after mixing and stir, be transferred in 120 ℃ of hydro-thermal axes reaction 15 hours, will react products therefrom and be transferred in culture dish and dry.To dry product and be positioned in crucible or quartz boat, and crucible or quartz boat are moved in high temperature process furnances, at 600 ℃, under air conditions, calcining is 9 hours, naturally coolingly can obtain Li ₃vO ₄sample.

Claims

1. a lithium ion battery Li ₃vO ₄negative material is characterized in that: take vanadic oxide, lithium carbonate and hexamethylenetetramine as raw material, adopt hydro thermal method to prepare Li through high temperature sintering ₃vO ₄.

2. lithium ion battery Li according to claim 1 ₃vO ₄negative material is characterized in that: this material is graininess, and average-size is less than 200nm.

3. a lithium ion battery Li ₃vO ₄the preparation method of negative material, it is characterized in that: lithium carbonate, vanadic oxide and hexamethylenetetramine are taken to shine mol ratio 2-5:1:2 ~ 10, dissolve and stir with distilled water, then being placed in hydrothermal reaction kettle reacts, the intermediate product that reaction is obtained is dried in 80 ℃ of baking ovens, subsequently in air under 500 ℃ of conditions calcining within 5 hours, obtain Li ₃vO ₄negative material.

4. lithium ion battery Li according to claim 4 ₃vO ₄negative material is characterized in that: hydrothermal temperature is 120 ℃, 10 ~ 30 hours reaction time.

5. lithium ion battery Li according to claim 4 ₃vO ₄negative material is characterized in that: under air conditions, and 400 ~ 700 ℃ of lower sintering 1 ~ 10 hour.