CN103824999B - A kind of cathode of lithium battery and preparation method thereof and lithium battery - Google Patents
A kind of cathode of lithium battery and preparation method thereof and lithium battery Download PDFInfo
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Abstract
The invention provides a kind of cathode of lithium battery and preparation method thereof, described cathode of lithium battery comprises collector and is positioned at the negative active core-shell material of collection liquid surface; Described negative active core-shell material is two layer composite structure, and the ground floor wherein near afflux side is made up of material with carbon element and the first material, and the second layer away from afflux side is made up of the first material and the second material; Described first material is selected from least one in elementary silicon, silicon-containing compound, and described second material is NASICON type solid electrolyte; The content of material with carbon element and the first material distribution gradient on described cathode of lithium battery thickness direction in described ground floor, and from collector more close to the content of position material with carbon element higher, from collector more close to the content of position first material lower.Present invention also offers the lithium battery adopting this negative pole.Adopt the lithium battery of negative pole provided by the invention, while acquisition is compared with height ratio capacity, also there is good cycle performance.
Description
Technical field
The invention belongs to technical field of lithium batteries, be specifically related to a kind of cathode of lithium battery and preparation method thereof and adopt the lithium battery of this cathode of lithium battery.
Background technology
At present, in lithium ion battery negative, general employing monolayer active material layer is made into slurry after mixing with binding agent, conductive agent, solvent etc., then adopts the technology of slit film to be coated in copper foil current collector and forms negative electrode.The active material that commercial Li-ion battery negative pole adopts is graphite-like material with carbon element, but its theoretical specific capacity only has 372mAh/g, limits the further raising of lithium ion battery specific energy.Silicon materials receive much concern as high power capacity Novel anode material.But silicon materials there occurs serious volumetric expansion and contraction in removal lithium embedded process, cannot image-stone ink equally stablized, fine and close SEI film, this limits the application of silicon materials as dynamic stabilization negative pole greatly.
No matter be graphite-like material with carbon element or silicon materials, the main component of its surface passivation SEI film is except the organic component that part is difficult to discriminating, major part is lithium carbonate and lithium fluoride inorganic component, and the two is not good lithium ion conductor, will certainly produce obstruction to lithium ion in the migration of negative terminal surface, and the formation of the two reduces the coulombic efficiency of battery for cost.Particularly silicon materials volume in cyclic process constantly expands, shrinks the accumulation causing the inert component such as lithium carbonate, lithium fluoride, and this not only consumes active lithium reversible in lithium battery, also counteracts that lithium ion is at negative pole migrating channels.Along with the carrying out of circulation, material granule is constantly split into less particle, the solid electrolyte film of particle surface is constantly destroyed and is again formed, the solid electrolyte film that final granule surface constantly thickens has blocked the electronic conductance between material, material and electrode lose electrical contact, become " dead capacity ", cause capacity attenuation in cyclic process.
In addition, in lithium battery, SEI film is uneven on negative pole thickness direction, and in existing cathode of lithium battery, do not focus on electrical conductivity passage and the ionic transport passages demand status in zones of different, so, when electrode is thicker or adopt the problem easily bringing cycle performance to decline during the more serious silicium cathode of side reaction.
Summary of the invention
The invention solves the negative pole that lithium battery in prior art adopts causes battery to there is the technical problem that specific capacity is low and cycle performance is poor.
The invention provides a kind of cathode of lithium battery, described cathode of lithium battery comprises collector and is positioned at the negative active core-shell material of collection liquid surface; Described negative active core-shell material is two layer composite structure, and the ground floor wherein near afflux side is made up of material with carbon element and the first material, and the second layer away from afflux side is made up of the first material and the second material; Described first material is selected from least one in elementary silicon, silicon-containing compound, and described second material is NASICON type solid electrolyte;
The content of material with carbon element and the first material distribution gradient on described cathode of lithium battery thickness direction in described ground floor, and from collector more close to the content of position material with carbon element higher, from collector more close to the content of position first material lower.
Present invention also offers the preparation method of described cathode of lithium battery, comprise the following steps:
S10, material with carbon element is mixed with the first material after be mixed with ground floor slurry, at collection liquid surface by casting machine by ground floor slurry curtain coating in collection liquid surface, after drying collection liquid surface formed ground floor;
S20, the first material is mixed with the second material after be mixed with second layer slurry, ground floor surface by slit film mode, second layer slurry is coated on ground floor surface, after drying ground floor surface formed the second layer, obtain described cathode of lithium battery.
Finally, the invention provides a kind of lithium battery, the barrier film comprising positive pole, negative pole and be arranged between positive pole, negative pole, described negative pole cathode of lithium battery provided by the invention.
Cathode of lithium battery provided by the invention, take into full account the concrete condition of SEI film uneven distribution on negative pole thickness direction in electrode production process, SEI film near afflux side is thinner, and it is thicker away from the SEI film on afflux side (namely near barrier film side), therefore the first material of height ratio capacity and the material with carbon element of high stability is being adopted near afflux side, and the gradient distribution on negative pole thickness direction of its content, thus the electron flux that can effectively increase near afflux side in described cathode of lithium battery, alleviate the cycle performance decline problem that electrical conductivity difference is brought; And adopting the first material of height ratio capacity and the second material of high ionic conductivity away from afflux side (namely near barrier film side), make cathode of lithium battery provided by the invention while acquisition is compared with height ratio capacity, the problem that the ionic conduction that the side reaction that can also effectively avoid the first material to continue causes blocks, thus ensure further to adopt the lithium battery of negative pole provided by the invention to have good cycle performance.
Embodiment
The invention provides a kind of cathode of lithium battery, described cathode of lithium battery comprises collector and is positioned at the negative active core-shell material of collection liquid surface; Described negative active core-shell material is two layer composite structure, and the ground floor wherein near afflux side is made up of material with carbon element and the first material, and the second layer away from afflux side is made up of the first material and the second material; Described first material is selected from least one in elementary silicon, silicon-containing compound, and described second material is NASICON type solid electrolyte;
The content of material with carbon element and the first material distribution gradient on described cathode of lithium battery thickness direction in described ground floor, and from collector more close to the content of position material with carbon element higher, from collector more close to the content of position first material lower.
The present inventor finds, in lithium battery, and the embedding lithium and lithium-inserting amount is maximum at first of the negative electrode near barrier film side, current potential is minimum and maximum with the contact area of electrolyte, so the SEI formed is thicker; On thickness of electrode direction its SEI film thickness of diverse location of negative pole different, be also different to the demand of lithium ion conductivity and electronic conductivity, wherein need larger lithium ion conductivity and lower to the requirement of electronic conductivity near barrier film side, and higher and lower to the requirement of lithium ion conductivity near the requirement of afflux side to electronic conductivity.
The present invention analyzes various negative material used in the prior art, finds: 1, existing lithium battery, does not all consider the inhomogeneities of SEI film on negative pole thickness direction in electrode production process; 2, when adopting graphite-like material with carbon element to make negative pole, can not affect the cycle performance of battery when negative pole thickness is less, but the problem because of lithium concentration gradient cannot be given full play to its removal lithium embedded performance by the active material when negative pole enlarged in thickness near afflux side; 3, when the material such as silicon, the tin making negative pole adopting change in volume larger, along with the lasting increase causing SEI film thickness is shunk in the volumetric expansion carrying out active material of circulation, the cycle performance of battery is had a strong impact on; 4, the SEI film lithium ion conductivity of natural formation is very low, and wherein the inorganic component of several molecule thickness just likely causes negative electrode active material to lose efficacy.
For above analysis, the present inventor passes through further to test discovery, in the present invention, by improving the distribution situation of active material in cathode of lithium battery, in one side matched electrodes, the varied in thickness of SEI film, keeps the cycle performance of the first material on the other hand.Particularly, in the present invention, described negative active core-shell material is two layer composite structure, and the ground floor wherein near afflux side is made up of material with carbon element and the first material, and the second layer away from afflux side is made up of the first material and the second material; The content of material with carbon element and the first material distribution gradient on described cathode of lithium battery thickness direction in described ground floor, and from collector more close to the content of position material with carbon element higher, from collector more close to the content of position first material lower.
In the present invention, the ground floor near afflux side is made up of material with carbon element and the first material.Wherein, material with carbon element, on the one hand for lithium secondary battery anode provides stable removal lithium embedded capacity, on the other hand for negative electrode provides good electron channel, can keep the quick conduction of electronics in charging and discharging lithium battery process, reduces ohmic polarization.First material is selected from elementary silicon, at least one in silicon-containing compound, it can provide higher specific capacity, but the accessory substance brightness that it produces in charge and discharge cycles process hinders the electron channel of negative pole on negative pole thickness direction, and in negative pole electron flux distribution gradient on negative pole thickness direction, electron flux near afflux side will far above the electron flux away from afflux side (namely near barrier film side), so by the first material and material with carbon element distribution gradient in a thickness direction, particularly, from collector more close to the content of position material with carbon element higher, from collector more close to the content of position first material lower, thus the electron flux that can effectively increase near afflux side in described cathode of lithium battery, alleviate the cycle performance decline problem that electrical conductivity difference is brought.
On the other hand, by electrolysis immersion profit and the double influence of lithium concentration gradient, lithium ion flux is also uneven on negative pole thickness direction, particularly negative pole is the maximum region of lithium ion flux away from the outer surface (namely the second layer is surperficial) on afflux side (namely near barrier film side), also be the most serious region of side reaction, so improve negative pole outer surface effectively can alleviate the circulatory problems that ionic conduction brings.
Based on carbonate-based solvent and hexafluorophosphoric acid lithium salts in existing electrolyte system, in the SEI film formed when the embedding lithium of negative pole, inorganic component is mainly based on lithium carbonate, lithium fluoride and lithia that ionic conductivity is lower, and most film for additive also cannot change the inorganic component in SEI.Therefore, in cathode of lithium battery provided by the invention, the second layer away from afflux side is made up of the first material and the second material, and described second material is the NASICON type solid electrolyte that lithium ion conductivity is better than natural SEI inorganic component.Described NASICON type solid electrolyte room temperature ionic conductivity can reach 10
-4s/cm; Such material can form the lithium phosphate matrix that ionic conductivity is better than lithium carbonate and lithium fluoride in embedding lithium process, such ion conductor is conducive to the stability improving electrolyte interface film, improve the ionic conductivity of inorganic component in interfacial film, avoid the first material volume and to expand the negative issue that the side reaction product that brings accumulates.Simultaneously, in the present invention, the first material also containing height ratio capacity in the second layer, the outer surface of cathode of lithium battery provided by the invention near barrier film side is made also to have higher specific capacity on the basis not affecting electrical conductivity, SEI film thickness in circulating battery process effectively can also be avoided to increase the ionic conduction Problem of Failure brought, ensure that the lithium battery of negative pole provided by the invention has good cycle performance further.
As previously mentioned, the content of material with carbon element and the first material distribution gradient on described cathode of lithium battery thickness direction in described ground floor, and from collector more close to the content of position material with carbon element higher, from collector more close to the content of position first material lower.Under preferable case, in described ground floor, the content of the first material is increased to the 20-60wt% of close second layer side gradually by the 0.1-2wt% near afflux side.Correspondingly, in described ground floor, the content of material with carbon element is reduced to the 40-80wt% of close second layer side gradually by the 99.9wt% near afflux side.
In the present invention, the described second layer is for ensureing the high ionic conductivity of negative pole outer surface, and the content distribution for wherein the first material and the second material does not have particular/special requirement.Under preferable case, facilitate the shaping of the second layer, in the described second layer, the content of the first material and the second material is uniformly distributed on described cathode of lithium battery thickness direction.More preferably, in situation, in the described second layer, the content of the second material is 5-50wt%.
In the present invention, the thickness of described ground floor is 80-150 micron, and the thickness of the second layer is 0.1-50 micron.
As scheduled, described first material is selected from least one in elementary silicon, silicon-containing compound.Wherein, described silicon-containing compound can be selected from silicon monoxide, silicon alloy or silico-carbo-oxygen pottery one or more, the present invention is not particularly limited.
Described second material is NASICON type solid electrolyte.As the common practise of those skilled in the art, NASICON is meant to Na+Super+ionic+Conductor, and Na wherein can be replaced by Li, and typical NASICON structure is by MO
6octahedron and XO
4tetrahedron concurrent connects and forms [M
2(XO
4)
3] rigid structure and then mirror-image arrangement form open three-dimensional structure, sodium or lithium ion move in a three-dimensional structure.NASICON type lithium solid electrolyte has higher ionic conductivity.Under preferable case, described second material is selected from LiTi
2(PO
4)
3, LiZr
2(PO
4)
3, LiGe
2(PO
4)
3, LiSn
2(PO
4)
3, LiPb
2(PO
4)
3, Li
3ti
2(PO
4)
3and one or more in the doping vario-property compound of aforementioned various material, but be not limited to this.
In the present invention, described material with carbon element is the material with carbon element that can reversibly embed and deviate from lithium ion known in the field, such as, can be selected from one or more in native graphite, Delanium, soft carbon, carbon black, thermal cracking carbon, carbon fiber, but be not limited to this.Under preferable case, described material with carbon element be selected from thermal cracking carbon (such as hard carbon), soft carbon (such as coke), Delanium (such as graphitized intermediate-phase carbon microballon), carbon fiber one or more.
Present invention also offers the preparation method of described cathode of lithium battery, comprise the following steps:
S10, material with carbon element is mixed with the first material after be mixed with ground floor slurry, at collection liquid surface by casting machine by ground floor slurry curtain coating in collection liquid surface, after drying collection liquid surface formed ground floor;
S20, the first material is mixed with the second material after be mixed with second layer slurry, ground floor surface by slit film mode, second layer slurry is coated on ground floor surface, after drying ground floor surface formed the second layer, obtain described cathode of lithium battery.
According to method provided by the invention, because the proportion of material with carbon element is great compared with the ratio of the first material, therefore in ground floor slurry casting processes, the sinking speed of material with carbon element obviously can be greater than the sinking speed of the first material, after curtain coating is completed, content content that is higher, the first material near the material with carbon element on afflux side is lower, and higher away from the material with carbon element content on afflux side content that is lower, the first material, thus obtains the ground floor structure of described distribution gradient on negative pole thickness direction.
Under preferable case, the condition of described curtain coating also comprises: casting rate is 0.1-0.8m/min, and casting machine vibration frequency is 5-500Hz.
The forming method of the described second layer is slit coating method, and the method is conventionally known to one of skill in the art, repeats no more in the present invention.
As the common practise of those skilled in the art, when preparing ground floor slurry, second layer slurry, also need to add binding agent and solvent, the binding agent adopted and solvent are the various binding agent and solvent that those skilled in the art prepare that electrode has often, and the present invention is not particularly limited.Such as, described binding agent can adopt sodium carboxymethylcellulose (CMC), styrene-butadiene latex (SBR), and solvent can adopt water, but is not limited to this.
Finally, the invention provides a kind of lithium battery, the barrier film comprising positive pole, negative pole and be arranged between positive pole, negative pole, described negative pole cathode of lithium battery provided by the invention.Lithium battery provided by the invention has higher specific capacity and good cycle performance.
In order to make technical problem solved by the invention, technical scheme and beneficial effect clearly understand, below in conjunction with embodiment, the present invention is further elaborated.Should be appreciated that specific embodiment described herein only in order to explain the present invention, be not intended to limit the present invention.
Embodiment 1
(1) take water as solvent, CMC and SBR be binding agent, according to quality than Delanium: elementary silicon: the proportions ground floor slurry of CMC:SBR=90:10:3:2;
(2) the ground floor slurry of 100g is placed in the casting machine that substrate is Copper Foil, control temperature 120 DEG C, vibration frequency 50Hz, casting rate are after 0.2m/min, drying time 5min, form on copper foil current collector surface the ground floor that thickness is 100 microns;
(3) take water as solvent, CMC and SBR be binding agent, according to quality than elementary silicon: phosphoric acid tin lithium LiSn
2(PO
4)
3: the proportions second layer slurry of CMC:SBR=65:30:3:2;
(4) second layer slurry is placed in slit device for coating, at ground floor surface-coated second layer slurry, forms the dry film that thickness is 10 microns after dry, obtain the cathode of lithium battery S1 of the present embodiment; The thickness of its ground floor is 100 microns, elementary silicon in ground floor along distribution gradient on negative pole thickness direction, silicone content increases to the 30wt% near second layer side gradually by the 0.1wt% near copper foil current collector side, and the content of graphite is reduced to the 65.24wt% of close second layer side gradually by the 95.14wt% of nearly copper foil current collector side; The thickness of (content of binding agent is 4.76%) second layer is 10 microns, elementary silicon and LiSn
2(PO
4)
3be uniformly distributed along on negative pole thickness direction in the second layer, and in the second layer, the content of phosphoric acid tin lithium is 30wt%.
(5) with above-mentioned cathode of lithium battery S1 for work electrode, lithium metal is to electrode, is assembled into button cell A1 in argon gas glove box.
(6) using above-mentioned cathode of lithium battery S1 as negative plate, adopt cobalt acid lithium be that positive electrode active materials adds binding agent, conductive agent and solvent respectively, through batching, coating, drying, roll-in, cut after make positive.The polypropylene diaphragm of positive and negative plate and 20 micron thickness is wound into the battery core of rectangular lithium ion battery, and seal in the rectangular cell aluminum hull of this battery core loading 5mm × 34mm × 50mm, make 053450 type lithium ion battery, then through fluid injection, ageing, change into, after partial volume, obtain the full battery B1 of the present embodiment.
Embodiment 2
Adopt the step identical with embodiment 1 to prepare cathode of lithium battery S2, the button cell A2 of the present embodiment and full battery B2, difference is:
In step (3), adopt titanium phosphate lithium LiTi
2(PO
4)
3replace the LiSn in embodiment 1
2(PO
4)
3.
Embodiment 3
Adopt the step identical with embodiment 1 to prepare cathode of lithium battery S3, the button cell A3 of the present embodiment and full battery B3, difference is:
In step (1), adopt the elementary silicon in silicon monoxide replacement embodiment 1, and quality is than Delanium: silicon monoxide: CMC:SBR=85:15:3:2;
In step (3), adopt the elementary silicon in silicon monoxide replacement embodiment 1, and quality is than silicon monoxide: LiSn
2(PO
4)
3: CMC:SBR=60:35:3:2;
In step (4), in the cathode of lithium battery S3 obtained, the thickness of its ground floor is 80 microns, silicon monoxide in ground floor along distribution gradient on negative pole thickness direction, silicon monoxide content increases to the 35wt% near second layer side gradually by the 0.3wt% near copper foil current collector side, and the content of graphite is reduced to the 60.24wt% of close second layer side gradually by the 94.94wt% of nearly copper foil current collector side; The thickness of the second layer is 20 microns, silicon monoxide and LiSn
2(PO
4)
3be uniformly distributed along on negative pole thickness direction in the second layer, and in the second layer, the content of phosphoric acid tin lithium is 35wt%.
Comparative example 1
(1) take water as solvent, CMC and SBR be binding agent, according to quality than graphite: elementary silicon: the proportions slurry of CMC:SBR=90:10:3:2;
(2) slurry that 100g step (1) is prepared is placed in slit device for coating, at copper foil surface coating slurry, forms the dry grinding that thickness is 110 microns after dry, obtain the cathode of lithium battery SC1 of this comparative example.
(3) with above-mentioned cathode of lithium battery SC1 for work electrode, lithium metal is to electrode, is assembled into button cell AC1 in argon gas glove box.
(4) using above-mentioned cathode of lithium battery S1 as negative plate, adopt cobalt acid lithium be that positive electrode active materials adds binding agent, conductive agent and solvent respectively, through batching, coating, drying, roll-in, cut after make positive.The polypropylene diaphragm of positive and negative plate and 20 micron thickness is wound into the battery core of rectangular lithium ion battery, and seal in the rectangular cell aluminum hull of this battery core loading 5mm × 34mm × 50mm, make 053450 type lithium ion battery, then through fluid injection, ageing, change into, after partial volume, obtain the full battery BC1 of the present embodiment.
Performance test
(1) specific capacity test
Get each 20 of button cell A1-A3 and AC1, on indigo plant strange BK-6016 secondary cell device for detecting performance, at 25 ± 1 DEG C, test each battery capacity.Testing procedure is as follows: shelve 30min; 0.2mA constant-current discharge is to 0.005V; 0.1mA constant-current discharge is to 0.005V; 0.05mA constant-current discharge is to 0.005V; Shelve 10 minutes; 0.2mA constant current charge is to 2.5V.Record active material quality in the specific capacity=test battery capacity/button cell of active material in each battery, average.Test result is as shown in table 1.Note: embedding lithium specific capacity is total specific capacity of adding up in discharge step, de-lithium capacity is total specific capacity of adding up in charge step.
(2) loop test
Getting each 20 of full battery B1-B3 and BC1, holding up on day BS-9300 secondary cell device for detecting performance, under 25 ± 1 DEG C of conditions, battery being carried out charge and discharge cycles test with 0.2C.Step is as follows: shelve 10min; Constant voltage charge ends to 4.2V/0.05C; Shelve 10min; Constant-current discharge, to 3.0V, is 1 circulation.Repeat this step, in cyclic process when battery capacity lower than discharge capacity first 80% time, loop termination, this cycle-index is the cycle life of battery, and often group is averaged.Test result is as shown in table 2.
Table 1
| Battery is numbered | A1 | A2 | A3 | AC1 |
| Embedding lithium specific capacity/mAh/g | 731 | 683 | 822 | 650 |
| De-lithium specific capacity/mAh/g | 599 | 594 | 616 | 507 |
| Efficiency/% first | 82 | 87 | 75 | 78 |
Table 2
| Battery is numbered | B1 | B2 | B3 | BC1 |
| Cycle life/time | 418 | 426 | 492 | 25 |
| The internal resistance of cell/m Ω after circulation | 63 | 71 | 79 | 106 |
As can be seen from the test result of upper table 1, adopt the battery sample that negative pole provided by the invention makes, its specific capacity and cycle performance are all obviously better than the battery sample in comparative example.
The foregoing is only preferred embodiment of the present invention, not in order to limit the present invention, all any amendments done within the spirit and principles in the present invention, equivalent replacement and improvement etc., all should be included within protection scope of the present invention.
Claims (10)
1. a cathode of lithium battery, described cathode of lithium battery comprises collector and is positioned at the negative active core-shell material of collection liquid surface; It is characterized in that, described negative active core-shell material is two layer composite structure, and the ground floor wherein near afflux side is made up of material with carbon element and the first material, and the second layer away from afflux side is made up of the first material and the second material; Described first material is selected from least one in elementary silicon, silicon-containing compound, and described second material is NASICON type solid electrolyte;
The content of material with carbon element and the first material distribution gradient on described cathode of lithium battery thickness direction in described ground floor, and from collector more close to the content of position material with carbon element higher, from collector more close to the content of position first material lower.
2. cathode of lithium battery according to claim 1, is characterized in that, in described ground floor, the content of the first material is increased to the 20-60wt% of close second layer side gradually by the 0.1-2wt% near afflux side.
3. cathode of lithium battery according to claim 1, is characterized in that, in the described second layer, the content of the first material and the second material is uniformly distributed on described cathode of lithium battery thickness direction, and the content of the second material is 5-50wt%.
4. the cathode of lithium battery according to any one of claim 1-3, is characterized in that, the thickness of described ground floor is 80-150 micron, and the thickness of the second layer is 0.1-50 micron.
5. the cathode of lithium battery according to any one of claim 1-3, is characterized in that, described first material is selected from least one in elementary silicon, silicon monoxide, silicon alloy or silico-carbo-oxygen pottery.
6. the cathode of lithium battery according to any one of claim 1-3, is characterized in that, described second material is selected from LiTi
2(PO
4)
3, LiZr
2(PO
4)
3, LiGe
2(PO
4)
3, LiSn
2(PO
4)
3, LiPb
2(PO
4)
3, Li
3ti
2(PO
4)
3and one or more in doping vario-property compound.
7. the cathode of lithium battery according to any one of claim 1-3, is characterized in that, described material with carbon element be selected from native graphite, Delanium, soft carbon, carbon black, RESEARCH OF PYROCARBON, carbon fiber one or more.
8. the preparation method of cathode of lithium battery according to claim 1, is characterized in that, comprises the following steps:
S10, material with carbon element is mixed with the first material after be mixed with ground floor slurry, at collection liquid surface by casting machine by ground floor slurry curtain coating in collection liquid surface, after drying collection liquid surface formed ground floor;
S20, the first material is mixed with the second material after be mixed with second layer slurry, ground floor surface by slit film mode, second layer slurry is coated on ground floor surface, after drying ground floor surface formed the second layer, obtain described cathode of lithium battery.
9. preparation method according to claim 8, is characterized in that, in step S10, the condition of described curtain coating comprises: casting rate is 0.1-0.8m/min, and casting machine vibration frequency is 5-500Hz.
10. a lithium battery, the barrier film comprising positive pole, negative pole and be arranged between positive pole, negative pole, is characterized in that, described negative pole is the cathode of lithium battery described in any one of claim 1-7.
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| CN108346772B (en) * | 2017-01-22 | 2021-06-15 | 北京好风光储能技术有限公司 | Lithium slurry battery and asymmetric electrode plate thereof |
| US20210104750A1 (en) * | 2017-03-31 | 2021-04-08 | Panasonic Corporation | Negative electrode for nonaqueous electrolyte secondary battery, and nonaqueous electrolyte secondary battery |
| CN110858642B (en) * | 2018-08-24 | 2021-12-28 | 荣盛盟固利新能源科技股份有限公司 | Preparation method of silicon/graphite/solid electrolyte composite negative electrode material |
| CN109148893A (en) * | 2018-08-27 | 2019-01-04 | 江苏中兴派能电池有限公司 | One kind being based on lithium ion battery negative material SiOx/C combination electrode and preparation method |
| CN112864374B (en) * | 2019-11-27 | 2022-06-03 | 郑州宇通集团有限公司 | Lithium cathode with gradient distribution of lithium content, preparation method thereof and lithium secondary battery |
| CN110911685B (en) * | 2019-11-28 | 2021-09-14 | 宁德新能源科技有限公司 | Composition for negative electrode, and protective film, negative electrode and device comprising same |
| CN111628141B (en) * | 2020-07-16 | 2021-05-25 | 珠海冠宇电池股份有限公司 | Silicon-doped negative pole piece and lithium ion battery comprising same |
| CN115241412A (en) * | 2022-06-17 | 2022-10-25 | 珠海冠宇电池股份有限公司 | Pole piece and battery |
| CN116111045B (en) * | 2023-04-11 | 2023-12-19 | 宁德新能源科技有限公司 | Positive electrode plate, preparation method thereof, secondary battery and electronic device |
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