CN100470917C - Lithium secondary battery, and preparation method - Google Patents
Lithium secondary battery, and preparation method Download PDFInfo
- Publication number
- CN100470917C CN100470917C CNB2005101174105A CN200510117410A CN100470917C CN 100470917 C CN100470917 C CN 100470917C CN B2005101174105 A CNB2005101174105 A CN B2005101174105A CN 200510117410 A CN200510117410 A CN 200510117410A CN 100470917 C CN100470917 C CN 100470917C
- Authority
- CN
- China
- Prior art keywords
- negative
- battery
- pole
- preparation
- active material
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
Abstract
The lithium secondary battery includes battery container as well as pole set and non-aqueous electrolyte sealed inside the container. The pole set includes anode, cathode, and diaphragm located between anode and cathode. The anode includes current collection body of anode, and anode material painted on the body. The cathode includes current collection body of cathode, and cathode material painted on the body. The cathode material includes cathode active material and binding agent. Median size D50 of cathode active material is 12-20 micros. Volume density of cathode material is 1.50-1.65 g/cm3. Improving median size of cathode active material and volume density of cathode material raises capacity of lithium secondary battery based on current technical bases. The invention also improves discharge performance at low temperature, and prolongs cycle life.
Description
Technical field
The invention relates to a kind of battery and preparation method thereof, specifically, the invention relates to a kind of Lithium Secondary Battery Of Nonaqueous Electrolyte and preparation method thereof.
Background technology
Lithium secondary battery refers to respectively the ion battery that constitutes as both positive and negative polarity with two compounds that can reversibly embed with the removal lithium embedded ion.Because of its specific energy height, operating voltage height, operating temperature range is wide, self-discharge rate is low, have extended cycle life, pollution-free, in light weight, advantage such as security performance is good, thereby application is extensive.
Lithium secondary battery generally includes battery container and is sealed in this battery container interior electrode group and nonaqueous electrolytic solution; Described electrode group comprises positive pole, negative pole and the barrier film between positive pole and negative pole; Described positive pole comprises positive electrode collector and applies positive electrode on it; Described positive electrode comprises positive active material, conductive agent and adhesive.Described negative pole comprises negative electrode collector and applies negative material on it; Described negative material comprises negative electrode active material and adhesive.Existing lithium secondary battery uses carbon-based material such as Delanium, native graphite etc. as negative electrode active material, uses lithium-nickel-cobalt-oxygen thing (LiNiCoO
2), lithium and cobalt oxides (LiCoO
2), lithium manganese oxide (LiMnO
2) wait lithium composite oxides as positive active material, the carbonate solution that uses the metal lithium salts is as electrolyte.
Prior art can not guarantee that other performances of battery such as low temperature performance, cycle performance etc. all keep higher level when improving battery capacity.For example, generally below 730 milliampere-hours ,-20 ℃ of about 30%, 400 circulation back battery capacity conservation rates of low temperature discharge rate are about 80% for the capacity of 423048A type lithium secondary battery; Though and the 423048A type battery of SANYO GS is brought up to the level of 750 milliampere-hours with battery capacity ,-20 ℃ of low temperature discharge rates of battery only are 10%, and behind the battery cycle charge-discharge 400 times, the capacitance conservation rate only is 70%.
Graphite is existing lithium secondary battery negative electrode active material commonly used, and theoretical capacity only is 372 milliampere-hour/grams, and it is very limited therefore to improve battery capacity by material itself.CN 1481041A discloses a kind of lithium secondary battery in order to reach the purpose that the capacity that improves battery improves low temperature performance and cycle life, and the mixture that uses artificial graphite particle and globular graphite particle is as negative electrode active material.But the preparation condition of described Delanium particle requires high, need be with the granulation thing of pulverizing stock that makes behind the whole mesophase pitch and the pitch that is in soft state and/or the granulation of thermosetting resin mixing and obtaining, 7000-1500 ℃ of following carbonization, under 2500-3000 ℃, carry out graphitization then, so processing cost is very high.
Summary of the invention
The objective of the invention is to overcome that prior art lithium secondary battery capacitance is low, low temperature performance difference and the short shortcoming of cycle life, provide a kind of battery capacity higher, low temperature performance is good, the lithium secondary battery that has extended cycle life.
Second purpose of the present invention provides the preparation method of above-mentioned lithium secondary battery.
The present inventor finds, the negative electrode active material broad particle distribution that prior art adopts (be distributed in 5-30 micron very on a large scale in), the volume density of negative material lower (generally below 1.50 gram/cubic centimetres) be cause that the lithium secondary battery capacitance is low, reason that low temperature performance difference and cycle life are lacked.The present inventor finds through research, need not to change the negative electrode active material composition, particle diameter by controlling negative electrode active material simultaneously and negative material volume density just can reach the purpose that the capacity that improves battery improves low temperature performance and cycle life in certain scope.
The invention provides a kind of lithium secondary battery, this battery comprises battery container and is sealed in this battery container interior electrode group and nonaqueous electrolytic solution; Described electrode group comprises positive pole, negative pole and the barrier film between positive pole and negative pole; Described positive pole comprises positive electrode collector and applies positive electrode on it; Described negative pole comprises negative electrode collector and applies negative material on it; Described negative material comprises negative electrode active material and adhesive, wherein, and the median particle diameter D of described negative electrode active material
50Be the 12-20 micron; The volume density of described negative material is a 1.50-1.65 gram/cubic centimetre.
The preparation method of lithium secondary battery provided by the present invention comprises positive pole and the negative pole for preparing battery, and will between positive pole and the negative pole barrier film be set, and constitutes the electrode group, and this electrode group is contained in the battery container, injects electrolyte, and is then that battery container is airtight; The preparation method of described positive pole is included in and is coated with coated positive pole material on the positive electrode collector, drying, calendering, cut-parts; The preparation method of described negative pole is included in and applies negative material on the negative electrode collector, drying, calendering, cut-parts; Described negative material comprises negative electrode active material and adhesive, wherein, and the median particle diameter D of described negative electrode active material
50Be the 12-20 micron, it is 1.50-1.65 gram/cubic centimetre that described calendering makes the volume density of described negative material.
Because the negative pole that lithium secondary battery provided by the present invention adopts has specific negative electrode active material median particle diameter D
50With the negative material volume density, make battery provided by the invention have the advantage that capacity high and low temperature discharge performance is good and have extended cycle life simultaneously.The negative electrode active material median particle diameter D of the lithium secondary battery that is provided as embodiment 1
50Be that 15 microns, negative material volume density are 1.55 gram/cubic centimetres, its battery capacity reaches 756.2 milliampere-hours, and 48.7%, 400 circulation back of-20 ℃ of low temperature discharge rates battery capacity conservation rate reaches 82%; Relatively battery capacity is at the existing lithium secondary batteries of the Comparative Examples 4 of 736.8 milliampere-hours ,-20 ℃ of about 25.9%, 400 circulation back battery capacity conservation rates 79.1% of low temperature discharge rate, and the lithium secondary battery that the embodiment of the invention 1 is provided is improved all having had obviously aspect battery capacity, low temperature performance and the cycle performance.
Description of drawings
Fig. 1 is that negative pole tow sides electrode material applies the effective area schematic diagram.
Embodiment
The invention provides a kind of lithium secondary battery, this battery comprises battery container and is sealed in this battery container interior electrode group and nonaqueous electrolytic solution; Described electrode group comprises positive pole, negative pole and the barrier film between positive pole and negative pole; Described positive pole comprises positive electrode collector and applies positive electrode on it; Described negative pole comprises negative electrode collector and applies negative material on it; Described negative material comprises negative electrode active material and adhesive, wherein, and the median particle diameter D of described negative electrode active material
50Be the 12-20 micron; The volume density of described negative material is a 1.50-1.65 gram/cubic centimetre.
Described negative electrode active material median particle diameter D
50, be the value of expression sample average granule size, promptly there is 50% particle diameter to be worth in institute's test sample product greater than this, 50% particle diameter is worth less than this.General median particle diameter D with the laser particle analyzer test sample
50The median particle diameter D of described negative electrode active material
50During less than 12 microns, because the granularity of negative electrode active material is too little, the gap between the negative material particle of negative pole calendering back is too little, causes nonaqueous electrolytic solution to be difficult to infiltrate through negative pole.Particularly the viscosity of nonaqueous electrolytic solution increases at low temperatures, has more increased the difficulty of negative pole absorption nonaqueous electrolytic solution, causes cryogenic property to descend.Because negative pole absorbs the nonaqueous electrolytic solution difficulty, also influenced the cycle performance of battery simultaneously.Median particle diameter D when negative electrode active material
50During greater than 20 microns, because the distance of the embedding people of lithium ion and Tuo embedding increases, guiding discharge decreased performance, cryogenic property also descend thereupon.
The volume density of described negative material is the compacted density of calendering back negative material.The volume density ρ of negative material
Press=m/ (s * d
Press), wherein m is the total weight of negative material on the negative pole of calendering back, s is for rolling the effective area that the back negative material covers negative electrode collector, d
PressThickness for negative pole calendering back negative electrode material layer.The effective area (S) that described negative material covers negative electrode collector is as shown in Figure 1: blank parts does not cover the negative electrode collector surface of negative material after for calendering, dash area is for still covering the negative electrode collector surface of negative material after rolling, the width of negative pole is W, total length is L, the length of blank parts is respectively L1 and L2, the length of dash area is respectively (L-L1) and (L-L2), then effective area S=[(L-L1)+(L-L2)]/2 * W.The volume density of described negative material is during less than 1.50 gram/cubic centimetres, and volume density is low excessively, causes between the negative material particle fluffy, and the particle diameter of particle itself is relatively large, the distance that lithium ion is embedded or take off embedding increases, and discharge performance is poor, causes low temperature performance to decrease; In the volume density 1.50-1.65 gram/cubic centimetre scope, rise with volume density, the negative pole internal resistance descends, and discharge performance improves, and low temperature performance improves thereupon; After volume density was greater than 1.65 gram/cubic centimetres, the space reduced between the negative material particle, the electrolyte permeability difficulty, and lithium ion is in the embedding of negative pole and take off the embedding difficulty that all becomes, so the low temperature performance variation, and battery capacity and cycle performance also reduce greatly.
Consisting of of described negative pole is conventionally known to one of skill in the art, and in general, negative pole comprises collector body and is coated in negative material on this collector body.Described collector body is conventionally known to one of skill in the art, for example can be selected from aluminium foil, Copper Foil, nickel plated steel strip, the Punching steel strip one or more, and the present invention selects for use Copper Foil to make collector body.
Consisting of of described negative material is conventionally known to one of skill in the art, and it comprises negative electrode active material and adhesive.Described negative electrode active material can be selected from one or more in native graphite, Delanium, petroleum coke, organic cracking carbon, carbonaceous mesophase spherules, carbon fiber, ashbury metal, the silicon alloy.
The adhesive of described negative material can be selected from one or more in polyvinyl alcohol, polytetrafluoroethylene, CMC (CMC), the butadiene-styrene rubber (SBR).In general, the content of described adhesive is the 0.5-8 weight % of negative electrode active material, is preferably 1-5 weight %.
Described positive pole can be to well known to a person skilled in the art various positive poles, and described positive pole generally includes collector body and is coated in positive electrode on this collector body.Described collector body can be a various collector body known in those skilled in the art, as aluminium foil, Copper Foil etc., for example can be selected from aluminium foil.Described positive electrode can be a various positive electrode known in those skilled in the art, generally includes the conductive agent that positive active material, adhesive and selectivity contain, and described positive active material can be selected from the positive active material of lithium secondary battery routine, as Li
xNi
1-yCoO
2(wherein, 0.9≤x≤1.1,0≤y≤1.0), Li
mMn
2-nB
nO
2(wherein, B is a transition metal, 0.9≤m≤1.1,0≤n≤1.0), Li
1+aM
bMn
2-bO
4(wherein ,-0.1≤a≤0.2,0≤b≤1.0, M is one or more in lithium, boron, magnesium, aluminium, titanium, chromium, iron, cobalt, nickel, copper, zinc, gallium, yttrium, fluorine, iodine, the element sulphur).
Positive electrode of the present invention has no particular limits adhesive, can adopt the various adhesive that can be used for lithium secondary battery known in the art.The mixture of preferred adhesive hydrophobicity adhesive and hydrophilic adhesive.The ratio of described hydrophobicity adhesive and hydrophilic adhesive has no particular limits, and can determine according to actual needs, and for example, the part by weight of hydrophilic adhesive and hydrophobicity adhesive can be 0.3:1-1:1.Described adhesive can use with the aqueous solution or emulsion form, also can use with solid form, preferably use with the aqueous solution or emulsion form, have no particular limits the concentration of described hydrophilic adhesive solution and the concentration of described hydrophobicity adhesive agent emulsion this moment, and the viscosity that can be coated with according to the slurry of positive pole that will prepare and cathode size and the requirement of operability are adjusted flexibly to this concentration.For example, the concentration of described hydrophilic adhesive solution can be 0.5-4 weight %, and the concentration of described hydrophobicity adhesive agent emulsion can be 10-80 weight %.Described hydrophobicity adhesive can be Kynoar (PVDF), polytetrafluoroethylene, butadiene-styrene rubber or their mixture.Described hydrophilic adhesive can be hydroxypropyl methylcellulose, sodium carboxymethylcellulose, hydroxyethylcellulose, polyvinyl alcohol or their mixture.Preferred adhesive is Kynoar (PVDF).The content of described adhesive is the 0.5-8 weight % of positive active material, is preferably 1-5 weight %.
Positive electrode provided by the invention can also optionally contain the common conductive agent that contains in the prior art positive electrode.Because conductive agent is used to increase the conductivity of electrode, reduce the internal resistance of battery, so the present invention preferably contains conductive agent.The content of described conductive agent and kind are conventionally known to one of skill in the art, for example, are benchmark with the positive electrode, and the content of conductive agent is generally 0-15 weight %, is preferably 0-10 weight %.Described conductive agent can be selected from one or more in other metal conductive agents such as conductive carbon black, acetylene black, ketjen carbon black, electrically conductive graphite, carbon fiber, furnace black, nickel powder, copper powder.
The solvent that is used to prepare anode sizing agent and cathode size of the present invention can be selected from conventional solvent, as being selected from N-methyl pyrrolidone (NMP), N, dinethylformamide (DMF), N, one or more in N-diethylformamide (DEF), methyl-sulfoxide (DMSO), oxolane (THF) and water and the alcohols.The consumption of solvent can be coated on the described collector body described slurry and gets final product.In general, the consumption of solvent is that to make the concentration of positive active material in the slurries be 40-90 weight %, is preferably 50-85 weight %.
If described adhesive is selected Kynoar (PVDF), then solvent is preferably N-methyl pyrrolidone (NMP), N, dinethylformamide (DMF), N, N-diethylformamide (DEF), methyl-sulfoxide (DMSO) or oxolane (THF); If described adhesive is selected polytetrafluoroethylene, butadiene-styrene rubber or their mixture and hydroxypropyl methylcellulose, sodium carboxymethylcellulose, hydroxyethylcellulose, polyvinyl alcohol or their mixture, then solvent is preferably water or ethanol.
Described barrier film has electrical insulation capability and liquid retainability energy, is arranged between positive pole and the negative pole, and is sealed in the battery case with positive pole, negative pole and electrolyte.Described barrier film can be the general various barrier films in this area, such as by those skilled in the art in the modified poly ethylene felt of respectively producing the trade mark, modified polypropene felt, ultra-fine fibre glass felt, vinylon felt or the nylon felt of known each manufacturer production and wettability microporous polyolefin film through welding or the bonding composite membrane that forms.
Described nonaqueous electrolytic solution is made up of nonaqueous solvents and the electrolyte that is dissolved in nonaqueous solvents.Above-mentioned nonaqueous solvents is not particularly limited, and can use known up to now nonaqueous solvents.Described nonaqueous solvents can be a various high boiling solvent of the prior art, low boiling point solvent or their mixture, for example can be selected from gamma-butyrolacton, vinyl carbonate, the ethyl-methyl carbonic ester, dimethyl carbonate, diethyl carbonate, carbonic acid first propyl ester, ethyl propyl carbonic acid ester, dipropyl carbonate, propene carbonate, vinylene carbonate, diphenyl carbonate, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, dimethoxy-ethane, diethoxyethane, sultone, and other is fluorine-containing, sulfur-bearing or contain the ring-type organosilane ester of unsaturated bond, organic acid anhydride, the N-methyl pyrrolidone, the N-methylformamide, the N-methylacetamide, acetonitrile, N, dinethylformamide, sulfolane, in the methyl-sulfoxide one or more.
The electrolyte that dissolves in the described nonaqueous solvents, there is no particular limitation equally in the present invention, can use the electrolyte that is generally used for Lithium Secondary Battery Of Nonaqueous Electrolyte.As lithium hexafluoro phosphate (LiPF
6), LiBF4 (LiBF
4), hexafluoroarsenate lithium (LiSbF
6), lithium perchlorate (LiClO
4), fluorocarbon based sulfonic acid lithium (LiCF
3SO
3), Li (CF
3SO
2)
2N, LiC
4F
9SO
3, chlorine lithium aluminate (LiAlCl
4), LiN (C
xF
2x+1SO
2) (C
yF
2y+1SO
2) in (x and y are the natural number of 1-10 in the formula), lithium chloride (LiCl) and the lithium iodide (LiI) one or more.Electrolytical concentration is generally the 0.1-2.0 mol in the nonaqueous electrolytic solution, is preferably the 0.7-1.6 mol.
The preparation method of Lithium Secondary Battery Of Nonaqueous Electrolyte provided by the invention comprises positive pole and the negative pole for preparing battery, and will between positive pole and the negative pole barrier film be set, and constitute the electrode group, this electrode group is contained in the battery container, inject electrolyte, then that battery container is airtight; The preparation method of described positive pole is included in and is coated with coated positive pole material on the positive electrode collector, drying, calendering, cut-parts; The preparation method of described negative pole is included in and applies negative material on the negative electrode collector, drying, calendering, cut-parts; Described negative material comprises negative electrode active material and adhesive, wherein, and the median particle diameter D of described negative electrode active material
50Be the 12-20 micron, it is 1.50-1.65 gram/cubic centimetre that described calendering makes the volume density of described negative material.
The condition of described calendering is the 0.5-3.0 MPa.Under these conditions, rolling the volume density that can make described negative material is 1.50-1.65 gram/cubic centimetre.
It is 7.5-10.5 milligram/square centimeter that described coating makes the coat side density of negative material on negative electrode collector, preferred 8.0-10.0 milligram/square centimeter.
It is 20.0-25.0 milligram/square centimeter that described coating makes the coat side density of positive electrode on positive electrode collector, preferred 20.0-23.5 milligram/square centimeter.
The coat side density p of described electrode material on collector body
Face=m
Face/ s
Face, m wherein
FaceBe the weight of electrode material coating, s
FaceBe the dressing area after applying.Just/when the negative pole area was identical, coat side density was low more, then just/negative pole top electrode active material is few more, so battery capacity is low more; But coat side density is low more, just/the negative pole internal resistance is low more, helping more under normal temperature and the cryogenic conditions, electronics and lithium ion just/migration on the negative pole, so the cryogenic property of battery and cycle performance are good more.Be that coat side density is low more, then battery capacity is more little, and cryogenic property and cycle performance are good more.The coat side density of described positive electrode is during less than 20.0 milligrams/square centimeter, and battery capacity does not reach requirement; During greater than 25.0 milligrams/square centimeter, bigger to battery cryogenic property and cycle performance influence.In like manner, the coat side density of described negative material is during less than 7.5 milligrams/square centimeter, and battery capacity does not reach requirement; During greater than 10.5 milligrams/square centimeter, bigger to battery cryogenic property and cycle performance influence.
Except the requirement according to negative pole rolling condition provided by the present invention and electrode material coat side density, the preparation process of other lithium secondary batteries is conventionally known to one of skill in the art.In general, will between the positive pole that prepare and the negative pole barrier film be set, constitute the electrode group, this electrode group is contained in the battery container, inject electrolyte, get final product battery container is airtight then.
The same with prior art, the preparation method of described positive pole is included on the positive electrode collector and applies the slurry that contains the conductive agent that positive active material, adhesive and selectivity contain, drying, and calendering promptly gets anodal after the cut-parts.Described drying usually under vacuum condition at 50-160 ℃, carry out under preferred 80-150 ℃.Described cut-parts are as well known to those skilled in the art, after calendering is finished, cut according to the anodal size of prepared battery request, obtain positive pole.
The preparation method of negative pole is identical with anodal preparation method, just replaces containing the slurry of positive active material, adhesive and conductive agent with the slurry of negative electrode active material and adhesive.
It is pure that all kinds of solvents of the present invention and reagent are analysis.
The present invention is described further below in conjunction with embodiment.
Embodiment 1
Present embodiment illustrates lithium secondary battery provided by the invention and preparation method thereof.
(1) Zheng Ji preparation
30 gram polyvinylidene fluoride (PVDF) are dissolved in about 500 gram N-methyl pyrrolidone (NMP) solvents make binder solution, the 940 gram LiCoO that will mix in advance then
2The acetylene black powder that serves as conductive agent with 30 grams joins in the above-mentioned solution, fully mixes and makes anode sizing agent; With tensile pulp machine this anode sizing agent is coated to thick 18 microns aluminium foil two sides equably, and to make coat side density be 23.5 milligrams/square centimeter.Through 125 ℃ of vacuum and heating dryings 1 hour, two rod milling train rolling formations, cut-parts make the positive pole of millimeter (wide) * 130,360 millimeters (length) * 43.5 micron (thick), contain the LiCoO of 5.25 grams of having an appointment on every positive pole
2
(2) preparation of negative pole
Detect median particle diameter D through laser particle analyzer
50Be 15 microns native graphite (soddif commodity, DAG22) powder 960 grams, the Kynoar (PVDF) that serves as adhesive with 40 grams fully mixes, and is dissolved into about 500 grams and serves as in the N-methyl pyrrolidone of solvent, fully mixes and makes cathode size.With tensile pulp machine this cathode size is coated to the two sides that thickness is 10 microns the Copper Foil that serves as collector body equably, makes that the coat side density of negative material is 9.5 milligrams/square centimeter.Through 125 ℃ of vacuum and heating dryings 1 hour, two rod milling trains are calendaring molding under 1.0 MPa pressure, and the volume density that makes its negative material is 1.55 gram/cubic centimetres.Cut-parts make the negative pole of millimeter (wide) * 130,330 millimeters (length) * 44.5 micron (thick), contain 2.25 graphite that restrain on the every negative pole.
(3) assembling of battery
To include in after positive pole, barrier film, negative pole lamination successively and the winding in 4.2 * 30 * 48 millimeters the square aluminum hull.
To contain 1 mole lithium hexafluoro phosphate (LiPF
6) ethylene carbonate: the Methylethyl carbonic ester: diethyl carbonate (EC/EMC/DEC) volume ratio is the about 2.6g of electrolyte of 1:1:1, injects above-mentioned battery.
Can obtain Lithium Secondary Battery Of Nonaqueous Electrolyte by said method.
Embodiment 2-6
Embodiment illustrates lithium secondary battery provided by the invention and preparation method thereof.
Method according to embodiment 1 prepares lithium secondary battery, and that different is negative electrode active material median particle diameter D
50, the volume density of negative material, the condition of calendering, the coat side density of negative material and the coat side density of positive electrode, as shown in table 1 below.
Table 1
| Embodiment | Negative electrode active material median particle diameter D 50(micron) | The volume density of negative material (gram/cubic centimetre) | Rolling condition (MPa) | The coat side density (milligram/square centimeter) of negative material | The coat side density (milligram/square centimeter) of positive electrode |
| Embodiment 2 | 12 | 1.65 | 2.0 | 11.0 | 25.5 |
| Embodiment 3 | 20 | 1.50 | 1.5 | 11.0 | 25.5 |
| Embodiment 4 | 15 | 1.55 | 1.7 | 11.0 | 25.5 |
| Embodiment 5 | 12 | 1.50 | 1.4 | 9.5 | 26.0 |
| Embodiment 6 | 20 | 1.65 | 2.0 | 11.0 | 23.5 |
Comparative Examples 1-4
Lithium secondary battery of Comparative Examples explanation prior art and preparation method thereof.
Method according to embodiment 1 prepares lithium secondary battery, and that different is negative electrode active material median particle diameter D
50, the volume density of negative material, the condition of calendering, the coat side density of negative material and the coat side density of positive electrode, as shown in table 2 below.
Table 2
| Comparative Examples | Negative electrode active material median particle diameter D 50(micron) | The volume density of negative material (gram/cubic centimetre) | Rolling condition (MPa) | The coat side density (milligram/square centimeter) of negative material | The coat side density (milligram/square centimeter) of positive electrode |
| Comparative Examples 1 | 5 | 1.40 | 0.4 | 9.5 | 23.5 |
| Comparative Examples 2 | 30 | 1.70 | 4.0 | 9.5 | 23.5 |
| Comparative Examples 3 | 15 | 1.70 | 4.0 | 9.5 | 23.5 |
| Comparative Examples 4 | 22 | 1.60 | 0.8 | 9.5 | 23.5 |
Embodiment 7
The following examples explanation, lithium secondary battery provided by the invention is on discharge capacity, low temperature performance and cycle performance, with respect to the part of improving of prior art.
25 ℃ of following discharge capacities of embodiment 1-6 and Comparative Examples 1-4 battery ,-20 ℃ of following discharge capacities, low temperature performance and cycle performances are measured.Assay method is as follows:
With battery be in temperature under 25 ℃ the environment with current charges to 4.2 volt of 750 milliampere-hours (1C), charging with current discharge to 3.0 volt of 750 milliampere-hours (1C), is write down its normal temperature capacity C then by 20 milliamperes in electric current
OftenEqually, in temperature be under-20 ℃ the environment with current charges to 4.2 volt of 750 milliampere-hours (1C), charging with current discharge to 3.0 volt of 750 milliampere-hours (1C), is write down its low temperature capacity C then by 20 milliamperes in electric current
LowThen low temperature performance is with C
Low/ C
OftenRepresent.
With battery be in temperature under 25 ℃ the environment with current charges to 4.2 volt of 750 milliampere-hours (1C), charging with current discharge to 3.0 volt of 750 milliampere-hours (1C), is write down its normal temperature capacity C then by 20 milliamperes in electric current
IniDo loop test with the identical condition of discharging and recharging then, the capacity of the 400th circulation is C
400, then cycle performance is with C
400/ C
IniExpression.
Measurement result is as shown in table 3.
Table 3
| Comparative Examples/embodiment | 25 ℃ of following discharge capacity C Often(milliampere-hour) | -20 ℃ of following discharge capacity C Often(milliampere-hour) | Low temperature performance C Low/C Often(％)? | Cycle performance C 400/C ini(％) |
| Comparative Examples 1 | 729.1 | 222.4 | 30.5 | 78.2 |
| Comparative Examples 2 | 723.5 | 154.1 | 21.3 | 74.3 |
| Comparative Examples 3 | 719.4 | 76.3 | 10.6 | 68.4 |
| Comparative Examples 4 | 736.8 | 190.8 | 25.9 | 79.1 |
| Embodiment 1 | 756.2 | 368.3 | 48.7 | 83.6 |
| Embodiment 2 | 748.3 | 318.0 | 42.5 | 80.9 |
| Embodiment 3 | 745.9 | 329.8 | 44.2 | 80.3 |
| Embodiment 4 | 746.8 | 331.7 | 44.4 | 80.8 |
| Embodiment 5 | 751.6 | 348.8 | 46.4 | 81.3 |
| Embodiment 6 | 753.6 | 339.3 | 45.0 | 82.0 |
From table 3 data shown in Comparative Examples 1-4 and the embodiment 1-6 as can be seen, the negative electrode active material median particle diameter D of lithium secondary battery provided by the invention
50In the 12-20 micrometer range, the volume density of the negative material of lithium secondary battery provided by the invention is between 1.50-1.65 gram/cubic centimetre simultaneously; In above-mentioned two scopes, graphite granule size and particle gap are moderate.Compare with the lithium secondary battery of Comparative Examples prior art, the lithium secondary battery provided by the invention not only discharge capacity of battery is improved, and the low temperature performance of battery and the cycle performance under the normal temperature also are improved simultaneously.
Data shown in embodiment 1 and the embodiment 4-6 it can also be seen that from table 3 in addition, when preparing lithium secondary battery of the present invention, if make negative material in the coat side density on the negative electrode collector in 7.5-10.5 milligram/square centimeter scope, make simultaneously positive electrode in the coat side density on the positive electrode collector in 20-25 milligram/square centimeter scope, the discharge capacity of battery be can also further improve, and the low temperature performance and the cycle performance of battery obviously improved.
Claims (10)
1. lithium secondary battery, this battery comprise battery container and are sealed in electrode group and nonaqueous electrolytic solution in this battery container; Described electrode group comprises positive pole, negative pole and the barrier film between positive pole and negative pole; Described positive pole comprises positive electrode collector and applies positive electrode on it; Described negative pole comprises negative electrode collector and applies negative material on it; Described negative material is made up of negative electrode active material and adhesive, wherein, and the median particle diameter D of described negative electrode active material
50Be 12 to less than 20 microns; The volume density of described negative material is a 1.50-1.65 gram/cubic centimetre.
2. battery according to claim 1, wherein, the volume density of negative material is a 1.55-1.65 gram/cubic centimetre.
3. battery according to claim 1, wherein, described negative electrode active material is selected from one or more in native graphite, Delanium, petroleum coke, organic cracking carbon, carbonaceous mesophase spherules, carbon fiber, ashbury metal, the silicon alloy.
4. battery according to claim 1, wherein, the adhesive of described negative material is selected from one or more in polyvinyl alcohol, polytetrafluoroethylene, CMC and the butadiene-styrene rubber.
5. the preparation method of the described battery of claim 1 comprises the positive pole and the negative pole that prepare battery, and will between positive pole and the negative pole barrier film be set, and constitutes the electrode group, and this electrode group is contained in the battery container, injects electrolyte, and is then that battery container is airtight; The preparation method of described positive pole is included in and is coated with coated positive pole material on the positive electrode collector, drying, calendering, cut-parts; The preparation method of described negative pole is included in and applies negative material on the negative electrode collector, drying, calendering, cut-parts; Described negative material is made up of negative electrode active material and adhesive, wherein, and the median particle diameter D of described negative electrode active material
50Be 12 to less than 20 microns, it is 1.50-1.65 gram/cubic centimetre that the condition of described calendering makes the volume density of described negative material.
6. according to the preparation method of the described battery of claim 5, wherein, the condition of described calendering is the 0.5-3.0 MPa.
7. according to the preparation method of the described battery of claim 5, wherein, it is 7.5-10.5 milligram/square centimeter that described coating makes the coat side density of negative material on negative electrode collector.
8. according to the preparation method of the described battery of claim 7, wherein, it is 8.0-10.0 milligram/square centimeter that described coating makes the coat side density of negative material on negative electrode collector.
9. according to the preparation method of the described battery of claim 5, wherein, it is 20.0-25.0 milligram/square centimeter that described coating makes the coat side density of positive electrode on positive electrode collector.
10. according to the preparation method of the described battery of claim 9, wherein, it is 20.0-23.5 milligram/square centimeter that described coating makes the coat side density of positive electrode on positive electrode collector.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2005101174105A CN100470917C (en) | 2005-10-31 | 2005-10-31 | Lithium secondary battery, and preparation method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2005101174105A CN100470917C (en) | 2005-10-31 | 2005-10-31 | Lithium secondary battery, and preparation method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1960052A CN1960052A (en) | 2007-05-09 |
| CN100470917C true CN100470917C (en) | 2009-03-18 |
Family
ID=38071607
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2005101174105A Active CN100470917C (en) | 2005-10-31 | 2005-10-31 | Lithium secondary battery, and preparation method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100470917C (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102214825A (en) * | 2010-04-02 | 2011-10-12 | 深圳市比克电池有限公司 | Cathode material of lithium ion battery and manufacturing method thereof as well as method for reducing low-temperature lithium separation |
| CN102214826A (en) * | 2010-04-08 | 2011-10-12 | 深圳市比克电池有限公司 | Lithium ion battery, negative electrode material, and method for improving low temperature discharging efficiency of lithium ion battery |
| CN102290577B (en) * | 2011-07-25 | 2016-03-23 | 东莞新能源科技有限公司 | A kind of negative pole of lithium ion battery |
| CN108539198B (en) * | 2017-03-03 | 2023-02-28 | 易案爱富科技有限公司 | Solvent for coating positive electrode active material for secondary battery, positive electrode active material slurry containing same, and secondary battery manufactured therefrom |
-
2005
- 2005-10-31 CN CNB2005101174105A patent/CN100470917C/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN1960052A (en) | 2007-05-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100481609C (en) | A super capacitance cell | |
| CN102738442B (en) | A kind of high energy density charge-discharge lithium battery | |
| CN201682023U (en) | Lithium ion battery | |
| JP5228576B2 (en) | Lithium ion secondary battery and electric vehicle power supply | |
| CN100557860C (en) | Battery cathode and comprise the lithium rechargeable battery of this negative pole | |
| CN102694200B (en) | Silicon-based negative lithium-ion battery and manufacturing method thereof | |
| CN103050290B (en) | Combining super capacitor device in a kind of | |
| CN101212070A (en) | Laminated Li-ion secondary battery and method for producing the battery | |
| CN108172823A (en) | Rich lithium manganese material, anode material for lithium-ion batteries, based lithium-ion battery positive plate, lithium ion battery and preparation method thereof | |
| CN104779397A (en) | Rechargeable lithium battery | |
| CN102005561A (en) | Positive electrode for nonaqueous electrolyte secondary battery and nonaqueous electrolyte secondary battery using the same | |
| CN110247013A (en) | Positive pole piece and electrochemical device containing same | |
| CN106602129A (en) | Multi-ion battery and preparation method thereof | |
| CN112614703B (en) | Negative electrode material of ionic capacitor and preparation method and application thereof | |
| CN101174682A (en) | Anode and method for producing the same and lithium ion secondary battery | |
| CN103151563A (en) | Polymer cell and preparation method thereof | |
| CN101453013A (en) | Negative electrode of lithium ionic cell, preparing method and cell thereof | |
| CN100470917C (en) | Lithium secondary battery, and preparation method | |
| CN102842706B (en) | Preparation method of lithium titanate material, lithium titanate material, and lithium ion battery | |
| CN101207189A (en) | Anode and preparation method thereof as well as lithium ion secondary battery | |
| CN108428563B (en) | A kind of lithium ion battery capacitor | |
| CN101414679A (en) | Composite material and preparation method thereof, and cathode and lithium battery | |
| CN110061189A (en) | Lithium secondary battery | |
| CN202749464U (en) | Polymer battery | |
| CN106654270A (en) | A cathode prepared from a hard carbon material, an energy storage apparatus comprising the cathode, uses of the hard carbon and a preparing method of the cathode |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| EE01 | Entry into force of recordation of patent licensing contract |
Assignee: Shenzhen BYD Lithium Battery Co., Ltd. Assignor: Biyadi Co., Ltd. Contract fulfillment period: 2008.4.25 to 2012.11.19 contract change Contract record no.: 2008440000071 Denomination of invention: Lithium secondary battery, and preparation method License type: Exclusive license Record date: 2008.5.13 |
|
| LIC | Patent licence contract for exploitation submitted for record |
Free format text: EXCLUSIVE LICENCE; TIME LIMIT OF IMPLEMENTING CONTACT: 2008.4.25 TO 2012.11.19 Name of requester: SHENZHEN BYD LITHIUM BATTERY CO., LTD. Effective date: 20080513 |
|
| EE01 | Entry into force of recordation of patent licensing contract |
Assignee: Shenzhen BYD Lithium Battery Co., Ltd. Assignor: Biyadi Co., Ltd. Contract fulfillment period: 2008.11.12 to 2014.4.30 contract change Contract record no.: 2008440000368 Denomination of invention: Lithium secondary battery, and preparation method License type: Exclusive license Record date: 20081113 |
|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| LIC | Patent licence contract for exploitation submitted for record |
Free format text: EXCLUSIVE LICENSE; TIME LIMIT OF IMPLEMENTING CONTACT: 2008.11.12 TO 2014.4.30; CHANGE OF CONTRACT Name of requester: SHENZHEN CITY BIYADILI BATTERY CO., LTD. Effective date: 20081113 |