A kind of method preparing lithium cell cathode material and lithium battery cathode plate
Technical field
The present invention relates to electrode material of lithium battery preparation field, be specifically related to a kind of Colophonium liquid phase coating and prepare lithium battery and bear
The method of pole material.
Background technology
Lithium battery compared with other secondary cell, have that running voltage is high, energy density big, discharging voltage balance, circulation
Life-span length and advantages of environment protection, have been widely used for the field such as portable type electronic product and electric tool, and be expected to
Become one of main energy sources supply of following hybrid vehicle and pure power vehicle.Negative material is to evaluate lithium battery integrated
One of key factor that can be good and bad.The lithium cell cathode material that commercialization at present uses is mainly charcoal class material, and it includes Yi Shi
Inkization charcoal, difficult graphitized charcoal and graphite.Graphite material good conductivity, degree of crystallinity is high, and theoretical embedding lithium capacity is high, has good layer
Shape structure and charging/discharging voltage platform, be one of the material of lithium battery primary study in recent years.Wherein, graphite material is divided into again sky
So graphite and big class of Delanium two, for relative native graphite, the interlamellar spacing of Delanium relatively greatly, degree of graphitization relatively low (≤
93%), easy graphitized carbon obtains through high temperature graphitization, therefore degree of crystallinity is relatively low, there is part Turbostratic.Meanwhile, artificial stone
Ink rough surface, porous, specific surface is relatively big, the most sensitive to the solvent in electrolyte so that the efficiency first of Delanium
The most relatively low with specific capacity (≤350mAh/g).Tie as some of lithium ion battery negative material itself for above Delanium
Structure defect, in order to obtain the negative material of high electrochemical performance, it is necessary to the modification that it is carried out a deep step surface and modification.
Being modified at present studying more to graphite material is cladding process, doping method, coating method, oxidation-reduction method and machine
Tool polishing etc..This patent utilizes the cladding process impact on artificial graphite cathode material for lithium ion batteries, uses the Delanium to be
Raw material, with Colophonium as covering material, is spray-dried by enclosed and high-temperature sintering process carries out coating modification to Delanium surface
And modification, the thickness being evenly coated stability and cladding of its medium pitch is the key of determining electrode material electrochemical performance.Its
Middle closed cycle spray is dried has synthesis technique simply, the low-cost advantage that solvent can recycle, and production efficiency is high, it is easy to
The advantages such as industrial-scale production.
Summary of the invention
The primary and foremost purpose of the present invention is to provide the preparation method of a kind of lithium cell cathode material, this artificial plumbago negative pole material
Expect first efficiency up to 93% and first specific capacity reach 355mAh/g, its first charge-discharge efficiency is high, specific capacity is high, solves people
Make that the irreversible capacity loss that graphite material exists when the actual application preparing cathode of lithium battery is big, relatively low the asking of specific capacity
Topic.
Another object of the present invention is to provide above-mentioned a kind of lithium battery cathode plate and preparation method thereof.
The present invention is achieved through the following technical solutions:
A kind of method preparing lithium cell cathode material, comprises the steps:
A, preparation artificial graphite material, (1) carries out mechanical activation comminution, then powder body is carried out mechanical ball milling and obtain micro-raw material
Fine powder body, and carry out fine powder staged care;(2) by the fine powder of parts by weight 90%-98% after classification and parts by weight 2% ~
10% Colophonium powder body mixes, and then the powder body of mix homogeneously is put into reaction 5-in the middle temperature reactor of 500-650 DEG C
10h, then discharging;(3) by discharging powder body through ball milling shaping fine powder staged care;(4) product of above-mentioned gained is carried out
The high temperature graphitization of 1500 DEG C-3000 DEG C insulation 30-50h processes, and the most again through staged care, i.e. can get Delanium material
Material;
B, prepared artificial graphite material is carried out Colophonium liquid phase coating, including: (1) is to step A(4) prepare artificial
Graphite material adds absolute ethyl alcohol and stirring dispersion and prepares dehydrated alcohol mixture;(2) tetrahydrofuran solution of Colophonium is prepared;(3)
The tetrahydrofuran solution of Colophonium is poured in dehydrated alcohol mixture with the ratio of 1:2-1:5, adds dehydrated alcohol regulation sizing material
Solids content to 10%-30%, then through closed cycle be spray-dried powder process, obtain presoma;(4) by presoma at indifferent gas
Being warming up to 700-1100 DEG C in body, constant temperature keeps 1-5h, prepares the lithium cell cathode material of pitch-coating.
Delanium raw material in step A is petroleum coke or calcined coke, and the staged care in described step A and step B obtains
To be particle diameter be the powder body of 5-20um;Artificial graphite material D50=10um that step A prepares.
Step A(2) described in the condition of reaction, reactor temperature is 500 ~ 650 DEG C, in still mixing speed be 20 ~
50r/min, the response time is 6-10h;Step A(4) described in high temperature graphitization process, graphitization temperature 2400 DEG C ~ 3000
DEG C, process time 36 ~ 72h.
Described step B(1), B(2) and B(3) in mixing speed be 400 ~ 2000r/min;Step B(3) described in be dried
Powder process is carried out by closed cycle spray drying machine, and described closed cycle spray drying machine is centrifugal atomizer, and its rotating speed is
15000 ~ 40000r/min, out temperature is respectively 100 ~ 150 DEG C and 80 ~ 100 DEG C, and charging rate is 20 ~ 30mL/min;Step
Rapid B(4) described in noble gas be purity be 99.999% nitrogen or purity be the argon of 99.999%, programming rate is 2
~5 DEG C/min..
Step B(2) the middle tetrahydrofuran solution preparing Colophonium, the weight of Colophonium is step B(1) artificial graphite material
5%-15%;Colophonium is 50-70:30-50 with the weight ratio of oxolane.
A kind of lithium battery cathode plate, including Copper Foil, Copper Foil is coated with coat, coat by binding agent, conductive agent with
And the lithium cell cathode material described in claim 1 is mixed to prepare.
A kind of cathode of lithium battery piece preparation method, comprises the steps: the preparation of (1) coat: by Colophonium liquid phase coating
Lithium cell cathode material, binding agent and conductive agent according to (88 ~ 93): (5 ~ 10): the weight ratio of 2 uniformly mixes, and obtains slurry;
(2) slurry of the coat obtained in step (1) is coated on Copper Foil, vacuum dried 5 ~ 24h, then roll-in, obtains institute
State lithium battery cathode plate.
The weight ratio of the lithium cell cathode material of Colophonium liquid phase coating, binding agent and conductive agent in described coat is
89:9:2。
Described binding agent is binding agent LA133 or polyvinylidene fluoride;Described conductive agent is conductive carbon black Super-P, second
Acetylene black, nano-sized carbon or conductive liquid.
Described coat thickness is 100 ~ 180 microns;Described roll-in thickness is 75 ~ 150 microns;Described vacuum drying temperature
Degree is 50 ~ 100 DEG C.
It is an advantage of the current invention that: the mode that the present invention uses closed cycle spray to be dried prepares powder body, Colophonium uniformly divides
It is dispersed on Delanium surface, after high-temperature heat treatment, forms one layer of unbodied charcoal after asphalt carbonization, be tightly wrapped in people
Make graphite, form the composite of a kind of " nucleocapsid " structure.The existence of clad not only reduces the specific surface area of material, resistance
Having stopped the entrance of organic solvent, reached to obtain the purpose of uniform, fine and close SEI film, meanwhile, surface Carbon Materials can fix graphite
Sheet, prevents coming off of graphite top layer so that efficiency first, specific capacity and the cyclical stability of material obtain certain raising.Cause
This, the first charge-discharge efficiency of the modified artificial graphite prepared by the present invention is high, specific capacity is high, good cycle.
In the preparation process of lithium cell cathode material, the dispersant applied and the kind of organic carbon source, sintering temperature
The structure of obtained lithium cell cathode material, size and pattern all can be produced the biggest by the conditions such as the technique with spray drying
Impact, and the structure of product, size and pattern can produce strong influence, and then impact to the performance of lithium cell cathode material
First charge-discharge, specific capacity and cycle performance to lithium cell cathode material.Therefore, in the present invention, inventor is by dividing
The process conditions such as powder kind, the kind of organic carbon source, the technique of spray drying, sintering temperature preferred, has obtained a kind of head
Secondary efficiency for charge-discharge is high, specific capacity is high, the artificial graphite material negative material of the Colophonium liquid phase coating modification of good cycle.
Found by detection, the artificial plumbago negative pole material after the Colophonium liquid phase coating modification that preparation method of the present invention obtains
Efficiency reaches 93% first, and reversible specific capacity reaches more than 355mAh/g first, higher than unmodified front Delanium (efficiency first
90%, reversible specific capacity 345mAh/g first).
Accompanying drawing explanation
Fig. 1 is the XRD figure of the lithium cell cathode material of the Delanium of the Colophonium liquid phase coating modification of embodiment 1 preparation
Spectrum;
Fig. 2 is the SEM figure of the lithium cell cathode material of the modified artificial graphite of the Colophonium liquid phase coating of embodiment 1 preparation;
Fig. 3 is the charge-discharge performance figure of simulated battery 1;
Fig. 4 is the charge-discharge performance figure of simulated battery 2;
Fig. 5 is the charge-discharge performance figure of simulated battery 3;
Fig. 6 is the charge-discharge performance figure of simulated battery 4.
Detailed description of the invention
Below in conjunction with embodiment and accompanying drawing, the present invention is described in further detail, but embodiments of the present invention do not limit
In this.Unless otherwise noted, all raw materials in the present invention and reagent are conventional commercial raw material, reagent.
Embodiment 1
(1) preparation of the lithium cell cathode material of Delanium:
(1) petroleum coke is carried out mechanical activation comminution, then powder body is carried out mechanical ball milling and obtains fine powder, and carry out fine powder
Staged care;
(2) fine powder after classification is mixed, then by the powder body of mix homogeneously with appropriate (5%) Colophonium powder body
Put into and in temperature reactor, react that (reactor temperature is 500 DEG C, and in still, mixing speed is 40r/min, and the response time is
8h), last discharging.
(3) discharging powder body is carried out shaping staged care again through shaping grader;
(4) product of above-mentioned gained is carried out high temperature graphitization process (2500 DEG C of insulation 36h), the most again at classification
Reason, i.e. can get artificial graphite material A(D50=10um).
(5) A prepared by step 1 is equipped with in the beaker of a certain amount of dehydrated alcohol, and stirs (400 r/min)
Dispersion 20min, obtains mixture B;
(6) weigh Delanium A mass 10% Colophonium be dissolved in a certain amount of oxolane, (1000 r/ at a high speed
Min) stirring 40min, makes Colophonium dissolve more abundant, crosses the sieve of 200 mesh, remove residue, obtain mixed liquor C.
(7) mixed liquor C is poured slowly in the beaker equipped with mixture B, is subsequently adding consolidating of dehydrated alcohol regulation slurry
Body burden, to 30%, continues quickly (2000 r/min) stirring 50min, then mixed liquor C carries out enclosed under certain conditions follows
Ring is spray-dried powder process, obtains presoma D, and wherein certain condition refers to: centrifugal atomizer rotating speed 30000r/min, imports and exports temperature
Degree is respectively 150 DEG C and 100 DEG C, charging rate 25mL/min;
(8) the presoma D that step (3) obtains is placed in reactor, in reactor, is passed through the nitrogen that purity is 99.999%
Gas is also warming up to 900 DEG C with the speed of 3 DEG C/min, and constant temperature keeps 4h, obtains the Delanium of described Colophonium liquid phase coating modification
Negative material.
(2) product finally obtained is carried out SEM pattern to detect mutually with XRD thing, SEM Shape measure result such as Fig. 1 institute
Showing, XRD thing phase testing result is as shown in Figure 2.As can be seen from Figure 1, from fig 1, it is seen that graphite granule surface portion covers
Dense pyrolytic carbon, reduces specific surface area, thus decreases electrolyte and the area of surface reaction, be conducive to improving head
Secondary efficiency.And from the XRD thing phase testing result of Fig. 2 it can be seen that, the standard card JCPDSno.041-of this collection of illustrative plates and cliftonite
1487 match, and do not occur chemical reaction to produce new thing phase.
(3) preparation of lithium battery cathode plate:
The lithium cell cathode material of the Colophonium liquid phase coating modification Delanium that the step () of 0.89g is prepared and 0.6g
Binding agent LA133(binding agent solids content be 15%), the conductive carbon black Super-P of 0.02g uniformly mix, furnishing slurry, be coated with
Overlaying on Copper Foil, coating thickness is 100 microns, and prepares through dry 10 hours of 100 DEG C of vacuum, roll-in (thickness is 85 microns)
Become lithium battery cathode plate 1.
Embodiment 2
(1) preparation of lithium cell cathode material:
(1) petroleum coke is carried out mechanical activation comminution, then powder body is carried out mechanical ball milling and obtains fine powder, and carry out fine powder
Staged care;
(2) fine powder after classification is mixed, then by the powder body of mix homogeneously with appropriate (5%) Colophonium powder body
Put into and in temperature reactor, react that (reactor temperature is 500 DEG C, and in still, mixing speed is 40r/min, and the response time is
8h), last discharging.
(3) discharging powder body is carried out shaping staged care again through shaping grader;
(4) product of above-mentioned gained is carried out high temperature graphitization process (2500 DEG C of insulation 36h), the most again at classification
Reason, i.e. can get artificial graphite material A(D50=10um).
(5) A prepared by step 1 is equipped with in the beaker of a certain amount of dehydrated alcohol, and stirs (800 r/min)
Dispersion 10min, obtains mixture B;
(6) weigh Delanium A mass 10% Colophonium be dissolved in a certain amount of oxolane, (1000 r/ at a high speed
Min) stirring 1h, makes Colophonium dissolve more abundant, crosses the sieve of 200 mesh, remove residue, obtain mixed liquor C.
(7) mixed liquor C is poured slowly in the beaker equipped with mixture B, is subsequently adding consolidating of dehydrated alcohol regulation slurry
Body burden, to 10%, continues quickly (1200 r/min) stirring 1h, then mixed liquor C carries out closed cycle under certain conditions
Being spray-dried powder process, obtain presoma D, wherein certain condition refers to: centrifugal atomizer rotating speed 15000r/min, out temperature
It is respectively 100 DEG C and 80 DEG C, charging rate 30mL/min;
(8) the presoma D that step (3) obtains is placed in reactor, in reactor, is passed through the nitrogen that purity is 99.999%
Gas is also warming up to 1100 DEG C with the speed of 5 DEG C/min, and constant temperature keeps 1h, obtains the Delanium of described Colophonium liquid phase coating modification
Negative material.
(2) preparation of lithium battery cathode plate:
The lithium cell cathode material of the Colophonium liquid phase coating modification Delanium that the step () of 0.89g is prepared and 0.6g
Binding agent LA133(binding agent solids content be 15%), the conductive carbon black Super-P of 0.02g uniformly mix, furnishing slurry, be coated with
Overlaying on Copper Foil, coating thickness is 100 microns, and prepares through dry 10 hours of 100 DEG C of vacuum, roll-in (thickness is 85 microns)
Become lithium battery cathode plate 2.
Embodiment 3
(1) preparation of lithium cell cathode material:
(1) petroleum coke is carried out mechanical activation comminution, then powder body is carried out mechanical ball milling and obtains fine powder, and carry out fine powder
Staged care;
(2) fine powder after classification is mixed, then by the powder body of mix homogeneously with appropriate (5%) Colophonium powder body
Put into and in temperature reactor, react that (reactor temperature is 500 DEG C, and in still, mixing speed is 40r/min, and the response time is
8h), last discharging.
(3) discharging powder body is carried out shaping staged care again through shaping grader;
(4) product of above-mentioned gained is carried out high temperature graphitization process (2500 DEG C of insulation 36h), the most again at classification
Reason, i.e. can get artificial graphite material A(D50=10um).
(5) A prepared by step 1 is equipped with in the beaker of a certain amount of dehydrated alcohol, and stirs (500 r/min)
Dispersion 30min, obtains mixture B;
(6) weigh Delanium A mass 10% Colophonium be dissolved in a certain amount of oxolane, (800 r/ at a high speed
Min) stirring 0.5h, makes Colophonium dissolve more abundant, crosses the sieve of 200 mesh, remove residue, obtain mixed liquor C.
(7) mixed liquor C is poured slowly in the beaker equipped with mixture B, is subsequently adding consolidating of dehydrated alcohol regulation slurry
Body burden, to 20%, continues quickly (2000 r/min) stirring 1h, then mixed liquor C carries out closed cycle under certain conditions
Being spray-dried powder process, obtain presoma D, wherein certain condition refers to: centrifugal atomizer rotating speed 20000r/min, out temperature
It is respectively 120 DEG C and 85 DEG C, charging rate 20mL/min;
(8) the presoma D that step (3) obtains is placed in reactor, in reactor, is passed through the nitrogen that purity is 99.999%
Gas is also warming up to 700 DEG C with the speed of 2 DEG C/min, and constant temperature keeps 5h, obtains the Delanium of described Colophonium liquid phase coating modification
Negative material.
(2) preparation of lithium battery cathode plate:
The lithium cell cathode material of the Colophonium liquid phase coating modification Delanium that the step () of 0.89g is prepared and 0.6g
Binding agent LA133(binding agent solids content be 15%), the conductive carbon black Super-P of 0.02g uniformly mix, furnishing slurry, be coated with
Overlaying on Copper Foil, coating thickness is 100 microns, and prepares through dry 10 hours of 100 DEG C of vacuum, roll-in (thickness is 85 microns)
Become lithium battery cathode plate 3.
Embodiment 4(comparative example)
(1) preparation of lithium cell cathode material in prior art:
(1) petroleum coke is carried out mechanical activation comminution, then powder body is carried out mechanical ball milling and obtains fine powder, and carry out fine powder
Staged care;
(2) fine powder after classification is mixed, then by the powder body of mix homogeneously with appropriate (5%) Colophonium powder body
Put into and in temperature reactor, react that (reactor temperature is 500 DEG C, and in still, mixing speed is 40r/min, and the response time is
8h), last discharging.
(3) discharging powder body is carried out shaping staged care again through shaping grader;
(4) product of above-mentioned gained is carried out high temperature graphitization process (2500 DEG C of insulation 36h), the most again at classification
Reason, i.e. can get artificial graphite material A(D50=10um).
(2) preparation of lithium battery cathode plate:
The lithium cell cathode material of the unmodified Delanium that the step () of 0.89g is prepared and the binding agent of 0.6g
LA133(binding agent solids content is 15%), the conductive carbon black Super-P of 0.02g uniformly mix, furnishing slurry, be coated in Copper Foil
On, coating thickness is 100 microns, and is prepared as lithium battery through dry 10 hours of 100 DEG C of vacuum, roll-in (thickness is 85 microns)
Negative plate 4.
In above-described embodiment 1 ~ 4 in the preparation of lithium battery cathode plate, binding agent is all chosen as binding agent LA132 and conduction
Agent is Super-P, and the weight ratio of each raw material is identical, and the most identical with roll-in thickness to lithium battery cathode plate coating thickness,
Only for preferably the effect of above-described embodiment being compared rather than to binding agent and conductive agent kind, raw material weight ratio
And the restriction of lithium battery cathode plate thickness.
Effect example
Lithium battery cathode plate 1~4 obtained by embodiment 1~4 is mixed molten with three components of 1mol/L LiPF6 respectively
Agent EC:DMC:EMC=1:1:1(volume ratio v/v/v), solution is electrolyte, and microporous polypropylene membrane is barrier film, and lithium sheet is positive plate
It is assembled into simulated battery 1~4.
Simulated battery is carried out 1~4 and carries out performance test, use (Wuhan Jin Nuo Electronics Co., Ltd.) LAND battery testing
The charging and discharging capacity cycle performance of system test simulation battery 1~4 respectively.Wherein, carry out constant current with the electric current of 100mA/g to fill
Specific discharge capacity loop test is tested, and charging/discharging voltage is limited in 0.01~2. 5V.Test result is as follows:
Fig. 3 is the charge-discharge performance figure of simulated battery 1.The lithium battery of simulated battery 1 electric discharge first as shown in Figure 3
Being respectively 384.2 mAh/g and 355mAh/g with charge specific capacity, cycle efficieny is up to 92.4 % first.Circulate 50 weeks, specific volume
Amount remains 350mAh/g, good cycle.
Fig. 4 is the charge-discharge performance figure of simulated battery 2.The lithium battery of simulated battery 2 electric discharge first as shown in Figure 4
Being respectively 384.9 mAh/g and 358 mAh/g with charge specific capacity, cycle efficieny is up to 93% first.Circulate 50 weeks, specific capacity
Remain 350.8mAh/g, good cycle.
Fig. 5 is the charge-discharge performance figure of simulated battery 3.The lithium battery of simulated battery 3 electric discharge first as shown in Figure 5
Being respectively 387.9 mAh/g and 360mAh/g with charge specific capacity, cycle efficieny is up to 92.9% first.Circulate 50 weeks, specific capacity
Remain 356.4 mAh/g, good cycle.
Fig. 6 is the charge-discharge performance figure of simulated battery 4.The lithium battery of simulated battery 4 electric discharge first as shown in Figure 6
Being respectively 383.3 mAh/g and 345 mAh/g with charge specific capacity, cycle efficieny is only 90 % first.Circulate 50 weeks, specific capacity
Remaining 327.7 mAh/g, cycle performance is poor.
Efficiency first and the specific capacity of simulated battery 4 are that the lithium of simulated battery 4 than the reason of simulated battery 1~3 difference
Unmodified Delanium rough surface, porous in battery cathode sheet 4, specific surface is relatively big, the quickest to the solvent in electrolyte
Sense.And embodiment 1 ~ 3 uses closed cycle spray drying mode and high temperature sintering methods to be prepared for Colophonium liquid phase coating modification
Artificial graphite material, in obtained powder body, Delanium Surface coating one layer of fine and close cracking charcoal, forms a kind of nucleocapsid knot
Structure, decreases specific surface area, effectively reduces the reaction of surface and electrolyte, meanwhile, surface Carbon Materials energy anchor stone ink sheet,
Prevent coming off of graphite top layer, substantially increase the first charge-discharge efficiency of material, specific capacity and cycle performance.
Above-described embodiment is the present invention preferably embodiment, but embodiments of the present invention are not by above-described embodiment
Limit, the change made under other any spirit without departing from the present invention and principle, modify, substitute, combine, simplify,
All should be the substitute mode of equivalence, within being included in protection scope of the present invention.