CN100524900C - Negative electrode for nonaqueous electrolyte secondary battery and process of producing the same - Google Patents
Negative electrode for nonaqueous electrolyte secondary battery and process of producing the same Download PDFInfo
- Publication number
- CN100524900C CN100524900C CNB2005800150648A CN200580015064A CN100524900C CN 100524900 C CN100524900 C CN 100524900C CN B2005800150648 A CNB2005800150648 A CN B2005800150648A CN 200580015064 A CN200580015064 A CN 200580015064A CN 100524900 C CN100524900 C CN 100524900C
- Authority
- CN
- China
- Prior art keywords
- active material
- negative pole
- current collection
- layer
- superficial layer
- 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.)
- Expired - Fee Related
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
Abstract
A negative electrode 1 for nonaqueous secondary batteries characterized by having an active material layer 5 and a metallic lithium layer 3 both between a pair of current collecting surface layers 4. The negative electrode 1 has two negative electrode precursors 2 each composed of the current collecting surface layer 4 and the active material layer 5 on one side of the surface layer 4. The two negative electrode precursors 2 are united with their active material layers 5 facing each other and with the metallic lithium layer 3 sandwiched therebetween. A metallic material having low capability of forming a lithium compound penetrates through the whole thickness of the active material layer 5.
Description
Technical field
The present invention relates to be used for the negative pole of nonaqueous electrolytic solution secondary batteries such as lithium rechargeable battery.In addition, the invention still further relates to the manufacture method of this negative pole.
Background technology
Proposed by on the negative pole of nonaqueous electrolytic solution secondary battery, attaching the technical scheme that lithium metal improves the anti-overdischarge characteristic of battery.For example, following technical scheme has been proposed: the lithium-contained composite oxide that uses transition metal at positive pole, negative pole uses carbon materials and positive plate, negative plate is wound in the spiral helicine nonaqueous electrolytic solution secondary battery with barrier film, in the part of the most peripheral that is equivalent to negative plate and do not attach lithium metal (consult spy open flat 5-No. 1444712 communiques, spies open flat 5-No. 144473 communiques, spies and open flat 7-No. 94211 communiques) on the part of positive plate.
But, in above-mentioned negative pole,, thereby cause coming off of this active material owing to the embedding of lithium ion and the expansion contraction of taking off the caused active material of embedding easily because active material is i.e. the most surperficial the coming out of the face that contact with nonaqueous electrolytic solution.As a result, the cycle life of battery reduces easily.In addition, because that lithium metal also is exposed to is the most surperficial, might can produce the dendrite of lithium in some cases, it comes off from negative pole, perhaps runs through barrier film and contacts with positive pole, thereby cause internal short-circuit or on fire.
And in nonaqueous electrolytic solution secondary battery, usually can in its manufacture process, sneak into the moisture of trace.In battery, moisture and nonaqueous electrolytic solution reaction, and make its decomposition.So the moisture that has proposed to make in the nonaqueous electrolytic solution secondary battery and comprised reduces, and the technical scheme (consult the spy and open communique 2001-No. 223030) that charge is improved.But, for moisture is reduced to the level that should satisfy, time and time that can overspending be uneconomic.
Dewater outside the branch, in collector body and active material, comprise micro-oxygen inevitably.Oxygen when discharging and recharging and lithium form compound.Because the bonding force of Li-O is more intense, therefore because the formation of this compound causes the amount of lithium that can reversible use to reduce.That is, irreversible capacity becomes big.
Summary of the invention
Therefore, the object of the present invention is to provide a kind of negative electrode for nonaqueous secondary battery that can overcome the various shortcomings of above-mentioned prior art.
The present invention has realized above-mentioned purpose by a kind of negative electrode for nonaqueous secondary battery is provided, and this negative electrode for nonaqueous secondary battery is characterised in that: comprise a pair of current collection usefulness superficial layer and active material layer and lithium metal layer between this a pair of current collection usefulness superficial layer.
In addition, the present invention also provides the preferred manufacture method of the manufacture method of negative electrode for nonaqueous secondary battery as above-mentioned negative pole, it is characterized in that:
On foils, form the current collection superficial layer by electroplating,
Form active material layer at this current collection on superficial layer, had the negative pole precursor of this current collection successively with superficial layer and this active material layer thereby on above-mentioned foils, form,
The mode of facing mutually each other with the described active material layer of each negative pole precursor sandwiches metallic lithium foil between two negative pole precursors, and it is as a whole that this metallic lithium foil and two negative pole precursors are formed by applying, then,
Described foils is peeled off with each negative pole precursor and separated.
In addition, the present invention also provides a kind of negative electrode for nonaqueous secondary battery, it is characterized in that:
This negative pole comprise by lithium compound form a pair of current collection that the low metal material of ability makes with superficial layer and at this a pair of current collection with the active material layer between superficial layer,
At at least one described current collection with forming a large amount of fine pores in the superficial layer, this fine pore described current collection with the surface of superficial layer on by perforate form, simultaneously to its thickness direction extension and can permeate nonaqueous electrolytic solution,
Described active material layer comprise embedded lithium, lithium compound forms the high active material particle of ability, and lithium compound forms the whole zone that the low metal material of ability is penetrated into the thickness direction of this active material layer in this active material layer,
And described negative pole does not have the conductive metal paper tinsel layer as core.
In addition, the present invention also provides the manufacture method of negative electrode for nonaqueous secondary battery, and the preferred manufacture method as above-mentioned negative pole is characterized in that:
On foils, form the current collection superficial layer by electroplating,
This current collection with superficial layer on coating comprise the conductive paste of active material particle and form active material layer, had the negative pole precursor of this current collection successively thereby on above-mentioned foils, form with superficial layer and this active material layer,
The mode of facing mutually each other with the described active material layer of each negative pole precursor sandwiches metallic lithium foil between two negative pole precursors, and it is as a whole that this metallic lithium foil and two negative pole precursors are formed by applying,
Be heated to the temperature that is enough to cause the lithium thermal diffusion, make lithium be diffused into the described active material layer from described metallic lithium foil, then,
Described foils is peeled off and separated from each negative pole precursor.
Description of drawings
Fig. 1 is the schematic diagram of structure of an execution mode of negative pole of the present invention.
Fig. 2 (a)～Fig. 2 (h) is the process chart of the method for manufacturing negative pole shown in Figure 1.
Fig. 3 is the schematic diagram of structure of the 2nd execution mode of negative pole of the present invention.
Fig. 4 is the schematic diagram of structure of the 3rd execution mode of negative pole of the present invention.
Fig. 5 is the schematic diagram of structure of the 4th execution mode of negative pole of the present invention.
Fig. 6 is the schematic diagram of structure of the 5th execution mode of negative pole of the present invention.
Fig. 7 is the curve chart of charge-discharge characteristic that has used the battery of the negative pole that is obtained by embodiment 5 and 6.
Fig. 8 is the curve chart of charge-discharge characteristic that has used the battery of the negative pole that is obtained by comparative example 3 and 4.
Fig. 9 (a) and (b) be the curve chart of charge-discharge characteristic of the battery that used the negative pole that obtains by embodiment 7 and comparative example 5.
Embodiment
Below, the present invention will be described based on preferred embodiment and with reference to accompanying drawing.In Fig. 1, schematically shown the structure of an execution mode of negative pole of the present invention.The negative pole 1 of present embodiment comprises that two negative pole precursors 2 and lithium metal layer 3 are as its basic component parts.Lithium metal layer 3 is clamped between the negative pole precursor 2.
Current collection is born the current collection function with superficial layer 4.In addition, current collection is used for also preventing that with superficial layer 4 active material that active material layer 5 comprised from shrinking and come off owing to the expansion that embeds the active material that the removal lithium embedded ion caused.Current collection preferably is made of the metal of the collector body that can become nonaqueous electrolytic solution secondary battery with superficial layer 4.Especially preferably the metal by the collector body that can become lithium secondary battery constitutes.As such metal, for example can listing, lithium compound forms the low metal material of ability.Specifically, can enumerate the alloy etc. of copper, nickel, iron, cobalt or these metals.In these metals, especially preferably use copper and mickel or their alloy.From the viewpoint of the intensity that improves negative pole 1, preferably use nickel.The constituent material of two current collection usefulness superficial layers 4 can be identical, also can use difference." it is low that lithium compound forms ability " is meant and can not forms intermetallic compound or solid solution with lithium, and the words lithium that perhaps promptly allows to form also is trace or extremely unstable.
It is thinner that the thick-film conductor body that each current collection is used with employed current collection in superficial layer 4 and the existing electrode is compared thickness.Specifically, be preferably about 0.3～10 μ m the thin layer about preferred especially 1～5 μ m.Like this, can almost completely and continuously cover active material layer 5 with the minimal thickness of necessity.As a result, can prevent the coming off of micronized active material owing to discharge and recharge.The thin current collection of above-mentioned scope preferably forms by plating as described later with superficial layer 4.In addition, two current collections can be identical with the thickness of superficial layer 4, also can be different.
Each current collection has perforate in its surface with superficial layer 4 and leads to a large amount of fine pore 6 of active material layer 5.Fine pore 6 is according to being present in this current collection usefulness superficial layer 4 to the mode of current collection with the thickness direction extension of superficial layer 4.By forming fine pore 6, nonaqueous electrolytic solution can be penetrated in the active material 5 fully, causes the reaction with active material fully.When current collection was carried out the section observation with superficial layer 4, fine voids 6 was that width is the fine degree about about 0.1 μ m～about 10um.Though be fine, fine pore 6 has the width of the degree that can permeate nonaqueous electrolytic solution.Especially because the surface tension of non-aqueous solution electrolysis liquor ratio aqueous electrolyte is little, even thereby the width of fine pore 6 very little, also can permeate fully.Fine pore 6 is preferably forming current collection with forming in the superficial layer 4 by electroplating.In addition, in the present embodiment, though formed fine pore 6 at each current collection in superficial layer 4, if at least 1 current collection with forming fine pore 6 in the superficial layer 4, also can reach desirable effect.
When using electron microscope that current collection is overlooked with the surface of superficial layer 4, the average perforated area of fine pore 6 is 0.1～50 μ m
2, be preferably 0.1～20 μ m
2, 0.5～10 μ m more preferably
2About.By setting the perforated area of this scope for, can in the sufficient infiltration of guaranteeing nonaqueous electrolytic solution, prevent coming off of active material effectively.In addition, can also improve charge/discharge capacity from the initial stage that discharges and recharges.When active material is particle, from more effectively preventing the viewpoint that comes off of this particle, above-mentioned average perforated area be preferably active material particle maximum secting area 0.1～50%, be preferably 0.1～20% especially.The maximum secting area of the particle of active material is meant, measures the particle diameter (D of active material particle
50Value) regards as and with this particle and to have D
50Maximum secting area during the ball of diameter of value.
When using electron microscope that current collection is overlooked with the surface of superficial layer 4, the summation of the perforated area of fine pore 6 is 0.1～20% with respect to the ratio (this ratio is called percent opening) of the area of field of view, is preferably 0.5～10%.Its reason is identical with the reason that perforated area with fine pore 6 is set at above-mentioned scope.And then, when using electron microscope that current collection is overlooked with the surface of superficial layer 4, preferably no matter choose what kind of visual field, at 100u based on this same reasons
All preferably there are 1～20,000, preferred especially 10～1,000, most preferably 50～500 fine pores 6 within sweep of the eye in m * 100 μ m foursquare.
Being positioned at current collection comprises lithium compound with the active material layer 5 of the positive inboard of superficial layer 4 and forms the high active material of ability.As this active material, for example can list silicon based material or tin based material, aluminium based material, germanium based material.Because each active material layer 5 covered with superficial layer 4 by each current collection, so can prevent from effectively to take off embedding and cause active material to come off owing to the embedding of lithium ion.Because active material can contact with electrolyte by fine pore 6, therefore not hindrance electrode reaction.
Comprise active material particle 7 and under the situation about constituting at active material layer 5, as this particle 7, can list for example i) particle of elementary silicon or tin simple substance, the ii) stuff and other stuff of silicon or tin and carbon at least, the iii) stuff and other stuff of silicon or tin and metal, the iv) compound particles of silicon or tin and metal, the v) stuff and other stuff of the compound particles of silicon or tin and metal, metallic, vi) on the surface of elementary silicon or tin simple substance particle, cover the particle that metal forms, vii) comprise the particle of their oxide.When the particle that uses ii), iii), iv), v) and vi), and use i) situation of the particle of elementary silicon or tin simple substance compares, has and can further suppress because the micronized advantage that the caused silicon based material of embedding is taken off in the embedding of lithium.In addition, also has the advantage that electronic conductivity can be provided to the silicon as semi-conductive shortage electronic conductivity.
The maximum particle diameter of active material particle 7 is preferably below the 50 μ m, more preferably below the 20 μ m.In addition, if with D
50The particle diameter of value representation particle 7 then is preferably 0.1～8 μ m, is preferably 1～5 μ m especially.If maximum particle diameter surpasses 50um, cause easily sometimes that then the coming off of particle 7, electrode life shorten.The not special restriction of the lower limit of particle diameter, the smaller the better.If consider the manufacture method of particle 7, lower limit is about 0.01 μ m.The particle diameter of particle 7 is measured by laser diffraction formula particle size distribution device, electron microscope observation.
If the amount of active material is very few with respect to the amount of whole negative pole 1, then be difficult to fully improve the energy density of battery, and if too much, the tendency that comes off that causes active material is easily arranged then.If consider these aspects, the amount of active material is preferably 5～80 weight % with respect to whole negative pole 1, more preferably 10～50 weight %, more preferably 20～50 weight %.The thickness of active material layer 5 can suitably be adjusted with respect to the ratio of whole negative pole etc. according to the amount of active material, is not special critical value in the present embodiment.Thickness when active material layer 5 constitutes by comprising active material particle 7 is generally 1～100um, is preferably especially about 3～40 μ m.
Comprise in active material layer 5 under the situation of active material particle 7, preferably lithium compound forms the whole zone that the low metal material of ability is penetrated into the thickness direction of active material layer 5.And preferably in this material that has permeated, there is active material particle 7.That is, preferred active material particle 7 does not come out on the surface of negative pole 1 basically and is embedded in the inside of current collection with superficial layer 4.Like this, active material layer 5 becomes firmly with the adhesiveness of current collection with superficial layer 4, has further prevented coming off of active material.In addition, guaranteed the electronic conductivity of current collection between superficial layer 4 and the active material by the above-mentioned material that is penetrated in the active material layer 5, therefore can effectively prevent to generate the active material of electric insulation, particularly can effectively prevent to generate the active material of electric insulation, thereby guarantee the current collection function in the deep of active material layer 5.As a result, can suppress to reduce as the function of negative pole.Can also realize the long lifetime of negative pole.This point is particularly advantageous under the situation of use as the material (for example silicon based material) of semi-conductive shortage electron conduction.
The lithium compound in whole zone that is penetrated into the thickness direction of active material layer 5 form the low metal material of ability preferably with constitute the metal material similar material of current collection with superficial layer 4.But,, also can use and constitute the different material of metal material of current collection usefulness superficial layer 4 so long as lithium compound formation ability is low.
Lithium compound forms the low metal material of ability and preferably runs through active material layer along the thickness direction of active material layer 5.Two current collections become by above-mentioned metal material and lithium metal layer 3 with superficial layer 4 and conduct thus, further improve the electronic conductivity as whole negative pole 1.That is, the whole negative pole 1 of present embodiment has the current collection function as a whole.Lithium compound forms the situation in whole zone that the low metal material of ability is penetrated into the thickness direction of active material layer 5, can be by being that the electron microscope scanning mapping of determination object is tried to achieve with this material.Be used for lithium compound is formed method for optimizing that the low metal material of ability is penetrated into active material layer 5 as described later.
Preferably, the particle 8 that in active material layer 5, except active material particle 7, also comprises conductive carbon cellulosic material or conductive metal material.Electronic conductivity further is provided for thus negative pole 1.From this viewpoint, the amount of the conductive carbon cellulosic material that is comprised in the active material layer 5 or the particle 8 of conductive metal material is a benchmark with active material layer 5, is preferably 0.1～20 weight %, is preferably 1～10 weight % especially.As the conductive carbon cellulosic material, can use for example particle of acetylene black or graphite etc.From the viewpoint of electronic conductivity further is provided, the particle diameter of these particles is preferably below the 40 μ m, is preferably especially below the 20 μ m.The not special restriction of the lower limit of the particle diameter of this particle, the smaller the better.But if consider the manufacture method of this particle, then its lower limit is about 0.01 μ m.
In the presence of nonaqueous electrolytic solution, and constitute local cell between the active material (negative electrode active material) at the lithium metal layer 3 of clamping configuration between two active material layers 5.Thus near the active material of lithium metal lithium metal layer 3 electrochemically embeds.Perhaps, the concentration gradient by lithium makes lithium embed in the active material.Like this, lithium metal layer 3 has been brought into play the effect of lithium source of supply.As a result, even lithium has been consumed owing to discharging and recharging, owing to can therefore solve the problem of the exhaustion of lithium from lithium metal layer 3 supply lithium.Can realize the long lifetime of negative pole 1 thus.In addition, even there is the moisture of trace in the battery constituent material (for example positive pole, electrolyte etc.) that with negative pole 1 is representative, owing to this moisture is consumed by reacting with lithium metal, so the moisture in the battery also can reduce.In addition, though comprise the oxygen of trace in collector body and the active material inevitably, captured by lithium metal.Therefore, can reduce the initial stage irreversible capacity, and improve the efficiency for charge-discharge (cycle characteristics) of each discharge cycles.In addition, lithium metal layer 3 does not come out on the surface of negative pole 1, but is positioned at the inside of negative pole 1, and lithium is embedded in the active material in addition, and the possibility that generates the dendrite cause internal short-circuit or lithium on fire is little.Produce the space in the lithium metal layer 3 after the lithium dissolving, the stress that expansion and contraction produced of the active material when discharging and recharging can be relaxed in this space, therefore has the micronized advantage that can suppress active material.
From making the angle of capacity restoration characteristic good, the amount of lithium metal discharges and recharges theoretical capacity with respect to initial stage of negative electrode active material and is preferably 0.1%～50%.Preferred scope is 5～50%, more preferably 10～40%, be preferably 20～40% especially.When using that for example silicon is as negative electrode active material, because silicon embeds lithium until reaching composition formula SiLi in theory
4.4Represented state, thus the embedded quantity of lithium to discharge and recharge theoretical capacity with respect to initial stage of silicon be that 100% situation is meant that lithium is embedded in the silicon until reaching composition formula SiLi
4.4Represented state.
If consider the strength maintenance and the energy density of negative pole 1, the thickness with negative pole 1 integral body of said structure is preferably 2～50 μ m, is preferably especially about 10～50 μ m.
Then, with reference to Fig. 2 the preferred manufacture method of negative pole shown in Figure 11 is described.At first, make negative pole precursor 2.In the manufacturing of negative pole precursor 2, shown in Fig. 2 (a), prepare foils 11.The not special restriction of the material of foils 11.Foils 11 preferably has conductivity.At this moment, foils 11 can not be metal also, so long as have conductivity just.But by using metallic foils 11, having after the manufacturing of negative pole precursor 2 can be by foils 11 being dissolved with foliation and recycling advantage.If consider recycling easiness, the material of foils 11 is preferably identical with the material of superficial layer 4 by electroplating the current collection that forms with aftermentioned.Foils 11 usefulness act on the support of making negative pole precursor 2, therefore, preferably have such intensity such as not producing wrinkle in manufacturing process.Therefore, the thickness of foils 11 is preferably about 10～50 μ m.
Then, shown in Fig. 2 (b), on a surface of foils 11, form by with the nappe 12 that constitutes the thin layer that current collection makes with the different material of the material of superficial layer 4.Then, form current collection superficial layer 4 by electroplating.By this operation, can easily be controlled at number and the perforated area of current collection with the hole 6 that forms on the superficial layer 4.
The not special restriction of the formation method of nappe 12.For example, can according to the relation of current collection with the formation method of superficial layer 4, select the formation method of nappe 12.Specifically, when forming current collection with superficial layer 4, consider that from making viewpoints such as efficient preferably nappe 12 also forms by electroplating by plating.Certainly, also can form nappe 12 by for example electroless plating, sputtering method, physical vapor vapour deposition method, chemical vapor coating method, sol-gel processing or ion plating.
By electroplating under the situation that forms nappe 12, can select suitable plating bath and plating condition according to the constituent material of nappe 12.For example,, can have following composition, and can use boron to fluoridize tin bath as electroplating bath constituting by tin under the situation of nappe 12.Bath temperature when using this plating bath is about 15～30 ℃, and current density is 0.5～10A/dm
2About.
·SnSO
4 30～70g/l
·H
2SO
4 60～150g/l
Cresol sulfonic acid 70～100g/l
As mentioned above, nappe 12 is used for collector body is become inhomogeneous state with the electronic conductivity of superficial layer 4.Therefore, if the electronic conductivity of the electronic conductivity of the constituent material of nappe 12 and foils 11 is different greatly, make current collection become uneven state immediately with the electronic conductivity of the formation face of superficial layer 4 by forming nappe 12.For example, using carbon is exactly this situation as the constituent material of nappe 12.On the other hand, constituent material as nappe 12, use the material that has with the electronic conductivity of foils same degree for example with the situation as the various metal materials of representative such as tin under, by forming nappe 12, current collection can not become uneven state immediately with the electronic conductivity of the formation face of superficial layer 4.Therefore, be made of these materials under the situation of nappe 12, the foils 11 that preferably will form nappe 12 is exposed under drying regime in the oxygen-containing atmosphere (for example atmosphere).Thus, can make the surface (and exposure of foils 11) oxidized (consulting Fig. 2 (c)) of nappe 12.By this operation, current collection is with the electronic conductivity of the formation face of the superficial layer 4 uneven state that becomes.Electroplate if carry out aftermentioned under this state, then the exposure of the surface of nappe 12 and foils 11 produces the electrolysis speed difference, can easily form fine pore 6.Degree of oxidation is not critical in the present invention.For example, by discovering of present inventor, in atmosphere, place about 10～30 minutes the foils 11 that has formed nappe 12 just enough.However, also can carry out forced oxidation to the foils 11 that has formed nappe 12.
The reason that is exposed to when being drying regime in the oxygen-containing atmosphere in the foils 11 that will form nappe 12 is in order to carry out oxidation effectively.For example when forming nappe 12, can after foils 11 is taken out from plating bath, use drier to make its drying, then in atmosphere, place official hour by plating.Using under the situations of dry process as the formation method of nappe 12 such as sputtering method or various vapour deposition methods, drying process is unwanted, can directly be placed in the atmosphere after forming nappe 12.
After with nappe 12 oxidations, shown in Figure 12 (d), on it, apply remover 13.Remover 13 is used for negative pole precursor 2 is peeled off on foils 11 from the beginning to the end well in strip step described later.As remover 13, preferably use organic compound, especially preferably use nitrogen-containing compound or sulfur-containing compound.As nitrogen-containing compound, preferred BTA (BTA), carboxyl benzotriazole (CBTA), tolyl-triazole (TTA), the N ' of using, N '-two (BTA ylmethyl) urea (BTD-U) and 3-amino-1H-1,2,4-triazole three azole compounds such as (ATA).As sulfur-containing compound, can list mercaptobenzothiazoler (MBT), sulfo-cyanuric acid (TCA) and 2-benzimidazole mercaptan (BIT) etc.Strictly speaking, the step that applies remover 13 is in order in the aftermentioned strip step negative pole precursor 2 to be peeled off on foils 11 from the beginning to the end well.Therefore, even omit this step, also can form current collection superficial layer 4 with a large amount of fine pore 6.
Then, shown in Fig. 2 (e), after having applied remover 13, current collection is come out with the constituent material electrolysis of superficial layer 4, form current collection superficial layer 4 by plating.With in the superficial layer 4, the fine pore 6 of above-mentioned diameter forms in a large number with the above-mentioned density that exists at formed current collection.In addition, in Fig. 2 (e), the mode that forms fine pore 6 with the position on the summit of nappe 12 is described, though this is easily, in fact, also might not form fine pore 6 in the position on the summit of nappe 12.Plating bath and plating condition can suitably be selected with the constituent material of superficial layer 4 according to current collection.For example, constituting current collection by Ni with under the situation of superficial layer 4, can use the Watts with following composition bathe and sulfamic acid as plating bath.Bath temperature when using these plating bath is preferably about 40～70 ℃, and current density is preferably 0.5～20A/dm
2About.
·NiSiO
4·6H
2O 150～300g/l
·NiCl
2·6H
2O 30～60g/l
·H
3BO
3 30～40g/l
Then, shown in Fig. 2 (f), with on the superficial layer 4, the conductive paste that coating comprises active material particle forms active material layer 5 at current collection.Slurry comprises active material particle, conductive carbon cellulosic material or conductive metal material, adhesive and retarder thinner etc.In these compositions,, can use polyvinylidene fluoride (PVDF), polyethylene (PE), ethene-propylene-diene monomers (EPDM) etc. as adhesive.As retarder thinner, use N-methyl pyrrolidone, cyclohexane etc.The amount of the active material in the slurry is preferably about 14～40 weight %.The amount of the particle of conductive carbon cellulosic material or conductive metal material is preferably about 0.4～4 weight %.The amount of adhesive is preferably about 0.4～4 weight %.In these compositions, add retarder thinner and prepare slurry.In addition, also can use above-mentioned vapour deposition process to replace the method for coating sizing-agent to form active material layer.If use this method, can not use retarder thinner and form active material layer, therefore have the advantage that need not the subsequent drying step.Drying steps exerts an influence for the oxidation of active material and adhesive and slurry retarder thinner.Therefore, the vapour deposition process of drying-free step can be suppressed at Min. with the influence of anticathode, so preferred this method.
Slurry dried coating film and after forming active material layer 5 is immersed in this foils 11 that has formed active material layer 5 to comprise in the plating bath that lithium compound forms the low metal material of ability and electroplates.By being immersed in the plating bath, plating bath is penetrated in the active material layer 5, arrives active material layer 5 and current collection with on the interface between the superficial layer 4, electroplates under this state.The result, in the inside of (a) active material layer 5 and (b) inner surface one side of active material layer 5 (promptly, in the face of surface one side of current collection with superficial layer 4), to separate out lithium compound and form the low metal material of ability, this material is penetrated into the whole zone of the thickness direction of active material layer 5.Like this, on foils 11, form negative pole precursor 2.
As the plating condition, for example using copper to form under the situation of the low metal material of ability as lithium compound, when using copper sulphate to be solution, the concentration of copper can be made as 30～100g/l, the concentration of sulfuric acid is made as 50～200g/l, the concentration of chlorine is made as below the 30ppm, and the liquid temperature is 30～80 ℃, and current density is 1～100A/dm
2When using cupric pyrophosphate to be solution, the concentration of copper can be made as 2～50g/l, the concentration of potassium pyrophosphate is made as 100～700g/l, and the liquid temperature is 30～60 ℃, and pH is 8～12, and current density is 1～10A/dm
2By these plating conditions of suitable adjustment, the whole zone of the thickness direction of the active material layer 5 of metal material infiltration.
Like this, be formed on the negative pole precursor 2 that has current collection usefulness superficial layer 4 and active material layer 5 on the foils 11 successively.Shown in Fig. 2 (g), use a pair of this negative pole precursor, the mode of facing mutually each other according to the active material layer 5 of negative pole precursor 2 sandwiches metallic lithium foil between two negative pole precursors 2.Like this, by metallic lithium foil 14 and two negative pole precursors 2 applyings are formed an integral body.At this moment, can be only the three be fitted by metallic lithium foil 14 and two negative pole precursors 2 is overlapping and operation that press together.Make under the situation become firm of fitting, can use conductivity jointing material such as conductive paste that their threes are fit together.
At last, shown in Fig. 2 (h), in the interface of current collection, negative pole precursor 2 is peeled off and separated from foils 11 with superficial layer 4 and foils 11.Obtain needed negative pole 1 like this.
The negative pole of the present embodiment that obtains like this constitutes nonaqueous electrolytic solution secondary battery with known positive pole, barrier film, non-aqueous electrolyte.Positive pole is by positive active material and conductive agent as required and adhesive being suspended in the appropriate solvent, making anode mixture, it is coated on the collector body, after the drying, by carry out rolling, compacting so that cut out, punching press makes.As positive active material, can above lithium nickel composite oxide, known positive active material such as complex Li-Mn-oxide, lithium cobalt composite oxide.As barrier film, preferably use synthetic resin nonwoven fabrics, polyethylene or polypropylene porous film etc.Under the situation of lithium secondary battery, nonaqueous electrolytic solution is to be dissolved in the solution composition that forms in the organic solvent by the lithium salts as supporting electrolyte.As lithium salts, can list for example LiClO
4, LiAlCl
4, LiPF
6, LiAsF
6, LiSbF
6, LiSCN, LiCl, LiBr, LiI, LiCF
3SO
3, LiC
4F
9SO
3Deng.
Then, with reference to Fig. 3～Fig. 6 embodiments of the present invention 2～5 are described.About these execution modes related, do not specify part, be fit to use the related detailed description of negative pole shown in Figure 1.
In the negative pole 1 that obtains like this, before the charging beginning, active material particle is in the state that has fully embedded lithium.Therefore, with respect to negative pole shown in Figure 1, embed the volume increase that lithium causes in the time of can further reducing owing to charging.In addition, because active material particle embeds lithium, in the part formation space bigger of metallic lithium foil 14 (consulting Fig. 2 (g)) than negative pole shown in Figure 1.The result has further been alleviated the generation that caused stress is shunk in the expansion of active material.
In Fig. 3, having described metallic lithium foil 14 (consulting Fig. 2 (g)) does not remain on the negative pole 1, but all be embedded in the active material particle 7, though this is easily, but metallic lithium foil also can remain in the negative pole 1, even also can access the negative pole with desirable performance in this case.Whether metallic lithium foil remains in the negative pole 1, and this depends on employed metallic lithium foil and the relation of the relative amount of active material, the temperature and time of thermal diffusion.Even the part of metallic lithium foil remains in the negative pole 1 before charging, lithium also can be consumed after discharging and recharging repeatedly, and its amount can reduce gradually.
In negative pole shown in Figure 41, between a pair of current collection is with superficial layer 4, be provided with an active material layer 5 and a lithium metal layer 3.The negative pole 1 of present embodiment is equivalent to, and only uses one deck active material layer in the negative pole 1 of the execution mode shown in Figure 1 that clamping configuration lithium metal layer 3 forms between two active material layers 5.
Formed the negative pole in a large amount of hole 9 on the negative pole 1 of negative pole 1 for execution mode shown in Figure 1 shown in Figure 5.Hole 9 uses the thickness direction of superficial layer 4 to extend in each surperficial perforate of negative pole 1 and along active material layer 5 and each current collection.In active material layer 5,9 wall comes out active material layer 5 in the hole.The effect in hole 9 roughly is divided into following 2 kinds.
One, the effect of in active material layer, supplying electrolyte by the active material layer 5 that in the wall in hole 9, comes out.Therefore, under the situation that forms hole 9, with in the superficial layer 4, also can not form above-mentioned fine pore 6 at current collection.In the wall in hole 9, though active material layer 5 come out,, because lithium compound forms between the particle 7 that the metal material of ability is penetrated into the active material in the active material layer, therefore can prevent that this particle 7 from coming off.
Its two, owing to discharge and recharge under the situation of change in volume of the active material particle 7 in the active material layer that causes, played and alleviated because the effect of the stress that this volume produced.Stress mainly produces on the in-plane of negative pole 1.Therefore, even produce stress owing to charging causes the volume of active material particle 7 to increase, this stress also is absorbed in the hole 9 that becomes the space.As a result, can effectively prevent the obvious distortion of negative pole 1.
Other effects in hole 9 have, and the gas release that is produced in the negative pole can be arrived its outside.Specifically, because the micro-moisture that comprises of institute in the negative pole produces H sometimes
2, CO, CO
2Deng gas.If these gases are assembled in negative pole, will cause polarization to increase, cause discharging and recharging loss.By forming hole 9, by this hole above-mentioned gas is discharged into the outside of negative pole, thereby can reduces by the caused polarization of this gas.In addition, other effects in hole 9 have the effect of negative pole heat release.Specifically, by the specific area of formation hole 9, thereby can effectively the heat that embedding produced along with lithium be discharged into the negative pole outside with the increase negative pole.In addition, if owing to the change in volume of active material particle produces stress, then therefore produce heating sometimes.By forming hole 9, alleviated this stress, thereby can suppress heating itself.
From electrolyte being fed to fully the viewpoint in the active material layer and alleviating effectively because the viewpoint of the caused stress of change in volume of active material particle, percent opening in the hole 9 of the surperficial perforate of negative pole 1, promptly the summation of removing the area in hole 9 with the apparent area on negative pole 1 surface multiply by 100 value again, be preferably 0.3～30%, be preferably 2～15% especially.Based on same reason, the aperture in the hole 9 of perforate in the surface of negative pole 1 is preferably 5～500 μ m, is preferably 20～100 μ m especially.In addition, preferably be made as 20～600 μ m by the spacing with hole 9, more preferably 45～400 μ m can be fed to electrolyte in the active material layer fully, and can alleviate the stress that change in volume produced by active material layer 7 effectively.In addition, when the arbitrary portion of observing the surface of negative pole 1, in the foursquare field of view of 1cm * 1cm, on average preferably have 100～250000, more preferably 1000～40000, preferred especially 5000～20000 holes 9.
The thickness direction of negative pole 1 also can be run through in hole 9.But consider in active material layer ample supply electrolyte and alleviate because the effect in the hole 9 of the stress that change in volume caused of active material particle, the thickness direction of negative pole 1 must not run through in hole 9, can and reach active material layer 5 at least in the surperficial perforate of negative pole 1.
The negative pole 1 of present embodiment can be made according to manufacture method shown in Figure 2.Specifically, carry out the step shown in Fig. 2 (a)～Fig. 2 (f) and obtain the negative pole precursor.Then, on the negative pole precursor, form hole 9 by the perforate processing of regulation.Then, carry out Fig. 2 (g) and (h) shown in operation.The not special restriction of the formation method in hole 9.For example can form hole 9 by laser processing.Perhaps, can carry out machine drilling by pin or drift.If both are compared, use laser processing to obtain cycle characteristics and the good negative pole of efficiency for charge-discharge easily.This be because, when laser processing, owing to dissolve and the metal material that solidifies has again covered the surface of the active material particle on the wall that is present in hole 9 by processing, thereby prevented directly coming out of active material, 9 wall comes off from the hole thereby prevented active material.When using laser processing, can after the step shown in for example Fig. 2 (f), carry out laser radiation facing to active material layer 5.In addition,, also can use the sand milling processing method, perhaps utilize optical lithography to form hole 9 as other the formation method in hole 9.Hole 9 preferably forms in the mode that equally spaced exists.This is because electrode integral body is induced reaction equably.
As the variation of negative pole shown in Figure 5, can list negative pole shown in Figure 61.In negative pole shown in Figure 6, on each face of conductivity paper tinsels 10 such as metal forming, formed lithium metal layer 3, and come clamping by an anticathode precursor 2.Utilize the negative pole 1 of present embodiment, can play the effect identical, in addition, also have by conductivity paper tinsel 10 and make negative pole 1 have more high-intensity effect with negative pole shown in Figure 5.
The present invention is not limited to above-mentioned execution mode.For example, in the negative pole of Fig. 3 and execution mode shown in Figure 4, can form the hole same with the hole that on the negative pole of Fig. 5 and execution mode shown in Figure 6, forms 9.In addition, negative pole shown in Figure 6 also can not form hole 9 therein.
In addition, the negative pole of above-mentioned each execution mode also can use separately, perhaps also can be used in combination a plurality of.Under latter event, can insert the conductivity paper tinsel (for example metal forming) that configuration constitutes core between the adjacent negative pole.
In addition, in above-mentioned each execution mode, current collection can be a single layer structure with superficial layer 4, but also at least one superficial layer can be made the sandwich construction more than 2 layers.For example, comprise by nickel (lithium compound forms the low element of ability) and lithium compound and form the high lower floor that element constituted of ability, form the double-decker on the high upper strata that element constituted of ability by at least one superficial layer is made, thereby can more effectively prevent the obvious distortion of the caused negative pole of change in volume of active material by copper (lithium compound forms the low element of ability) and lithium compound.When the current collection superficial layer is sandwich construction, this current collection with the lithium compound that comprised in the superficial layer form the low metal material of ability at least a can be be immersed in active material layer 5 in lithium compound form the low different material of metal material of ability.Perhaps, each current collection with the lithium compound that comprised in the superficial layer form the low metal material of ability can all be be immersed in active material layer 5 in lithium compound form the low different material of metal material of ability.
In addition, when current collection with the constituent material of superficial layer be immersed in the active material layer 5 material not simultaneously, be immersed in metal material in the active material layer 5 and may reside in active material layer 5 and current collection boundary part with superficial layer.Perhaps, the metal material that is immersed in the active material layer 5 can be crossed the part that this boundary part constitutes current collection usefulness superficial layer.Otherwise current collection also can be crossed this boundary part with the constituent material of superficial layer and be present among the active material layer 5.
In addition, in active material layer 5, make lithium compound form the operation that the low metal material of ability is separated out, the metal material of being separated out in the active material layer 5 can be made the different sandwich constructions more than 2 kinds by using the different plating bath more than 2 kinds.
In addition, in manufacture method shown in Figure 2, though be to form active material layer 5, also can use film formation methods such as chemical vapor coating method, physical vapor vapour deposition method, sputtering method, galvanoplastic to form the active material layer 5 that the thin layer by active material layer forms by the conductive paste that comprises active material particle.
Embodiment
Below, the present invention will be described in more detail by embodiment.But scope of the present invention is not limited to this embodiment.
[embodiment 1]
Make negative pole shown in Figure 5.At room temperature the copper foils (thickness is 35 μ m) that obtains by electrolysis is used acid elution 30 seconds.Then at room temperature with pure water washing 30 seconds.Then, foils is immersed in the tin plating bath with following composition electroplates, form the nappe that constitutes by tin.Current density is set at 2A/dm
2, bathe temperature and be set at 30 ℃.Anode has used tin electrode.Electric current has used direct current.Nappe forms the thickness of 20 μ m unevenly.After from plating bath, taking out, washed for 30 seconds, in atmosphere, after the drying, placed 15 minutes, carry out the oxidation of nappe with pure water.
·SnSO
4 50g/l
·H
2SO
4 100g/l
Cresol sulfonic acid 100g/l
With the foils that formed nappe dipping 30 seconds in remaining on 40 ℃ the CBTA solution of 3g/l.Carry out peel ply by this operation and form processing.After peel ply forms processing, from solution, take out, with pure water washing 15 seconds.
Then, foils is placed on H
2SO
4/ CuSO
4Be to electroplate in the plating bath.Thus in the formation of foils form the current collection superficial layer that is made of copper on the surface of nappe.Consisting of of plating bath: CuSO
4250g/l, H
2SO
470g/l.Current density is set at 5A/dm
2Current collection forms the thickness of 5 μ m with superficial layer.After taking out from plating bath, pure water washed for 30 seconds, and dry in atmosphere.
Then, current collection with superficial layer on the coating slurry that comprises active material particle reach 20 μ m until thickness, thereby form active material layer.Active material particle by Si form, average grain diameter D
50=2 μ m.Slurry consist of active material: acetylene black: butadiene-styrene rubber=98:2:1.7.
The foils that has formed active material layer is immersed in the Watts bath with following composition,, carries out the infiltration of nickel with respect to active material layer and electroplate by electrolysis.Current density is 5A/dm
2, bathing temperature is 50 ℃, pH is 5.Anode uses nickel electrode.Power supply uses DC power supply.After from electroplating bath, taking out, washed for 30 seconds with pure water, dry in atmosphere then.Obtain being carried on the negative pole precursor on the foils like this.The results verification of electron microscope observation has formed fine pore at the current collection of this negative pole precursor on superficial layer in a large number.
·NiSiO
4·6H
2O 250g/l
·NiCl
2·6H
2O 45g/l
·H
3BO
4 30g/l
Facing to negative pole precursor irradiation YAG laser, form the hole of running through this negative pole precursor regularly.The diameter in hole is 24 μ m, and spacing is 100 μ m (10000 holes/cm
2), percent opening is 4.5%.
Then, the thickness that uses an anticathode precursor clamping and negative pole precursor to separate preparation is the metallic lithium foil of 30 μ m.Clamping is to carry out according to the mode that the active material layer of each negative pole precursor is faced each other mutually.Like this, each negative pole precursor and lithium metal are fit together to form an integral body.At last, foils and current collection are peeled off with superficial layer and obtained needed negative pole.The amount of the lithium metal in the negative pole is 30% with respect to the initial stage charging theoretical capacity of the active material that is comprised in the negative pole.
Use resulting negative pole, make nonaqueous electrolytic solution secondary battery by following method.Capability retention after discharge capacity after 1 circulation of this battery, the rate of change of negative pole thickness and 100 circulations is measured by the following method and is calculated.Their result is as shown in table 1 below.
[making of nonaqueous electrolytic solution secondary battery]
The negative pole that use embodiment and comparative example obtain uses LiCoO as work electrode
2As to electrode.To electrode is by being to be coated with LiCoO on the Al paper tinsel of 20 μ m at thickness
2Until reaching 4mAh/cm
2Make.The ratio of positive electrode capacity and capacity of negative plates (the former: the latter) be set at 1:2.Two electrodes are faced each other mutually across barrier film.Use LiPF
6The mixed solution of/ethylene carbonate and dimethyl carbonate (volume ratio of 1:1) is as nonaqueous electrolytic solution, and makes nonaqueous electrolytic solution secondary battery by conventional method.
[1 circulation after discharge capacity]
Measure the discharge capacity of the per unit area of negative pole.
[rate of change of negative pole thickness]
The HS displacement battery that uses precious Izumi Ltd. to make, mensuration is along with the variation of the thickness of the negative pole of the charging of 1 circulation.In this displacement battery, measure negative pole+barrier film+anodal LiCoO
2Whole varied in thickness.But positive pole hardly can be owing to discharge expands, and the varied in thickness of negative pole is very big to the contribution rate of the varied in thickness of integral body, and therefore the varied in thickness of measuring is the variation of negative pole basically.
[100 circulation after capability retention]
Measure the discharge capacity after 100 circulations, should be worth divided by maximum negative discharge capacity, and multiply by 100, and calculate capability retention.
[comparative example 1]
Except not using metallic lithium foil, outside the mode that an anticathode precursor is faced each other mutually according to their active material layer is overlapping, adopt the method identical with embodiment 1, obtain negative pole.At resulting negative pole, carry out the evaluation identical with embodiment 1.The result is as shown in table 1.
Table 1
As the result of table 1 know show, can judge, used the discharge capacity and the capability retention height of battery of the negative pole of embodiment 1.In addition, the rate of change of negative pole thickness is little.In contrast, used the negative pole thickness change of battery of negative pole of the comparative example 1 that does not adopt the lithium paper tinsel big, and capability retention is low.
[embodiment 2～4 and comparative example 2]
In present embodiment and comparative example, to estimating by the difference of the different caused negative pole performance of the amount of the lithium metal that is comprised in the negative pole.Implement to use the perforate processing of YAG laser and the amount of lithium metal is made as the value shown in the table 2 except anticathode precursor not, make negative pole the samely with embodiment 1.Resulting negative pole has structure shown in Figure 1 (but except comparative example 1).The results verification of electron microscope observation has formed a large amount of fine pores at current collection on superficial layer.
At resulting negative pole, measure charging capacity and discharge capacity after 1 circulation.The result is as shown in table 2.In table 2, also put down in writing the capacity invertibity after 1 circulation simultaneously.Capacity invertibity after 1 circulation is meant, the charging capacity of the discharge capacity after 1 circulation after divided by 1 circulation be multiply by 100 and the value that obtains again.In addition, electrode is used lithium metal.Therefore, not comprising by to the irreversible capacity that electrode produced, mainly is can the former irreversible capacity of calculating by negative pole produced.In addition, owing to be not subjected to discharging and recharging so all told of negative pole all is carried out by to the capacity limit that electrode caused.
Table 2
As the result of table 2 know show, can judge that with respect to the negative pole of comparative example, the capacity invertibity after 1 circulation of the negative pole of each embodiment is bigger.Can think that its reason is because the lithium metal that comprised in the negative pole by each embodiment, make the performance of anticathode produce dysgenic moisture and be removed, and oxygen also be captured.In addition, in embodiment 3 and 4, it is because the lithium metal that adds helps to discharge and recharge reaction in advance that the capacity invertibity after 1 circulation surpasses 100 reason.
[ embodiment 5 and 6 and comparative example 3 and 4]
In present embodiment and comparative example, to estimating by the difference of the negative pole performance that difference caused of the moisture containing ratio in the negative pole.Except anticathode precursor not implements to use the perforate processing of YAG laser, and the amount of lithium metal is set at outside the initial stage charging theoretical capacity 40% with respect to silicon, with the embodiment 1 the same negative pole of making.Resulting negative pole has structure shown in Figure 1.The results verification of electron microscope observation has formed a large amount of fine pores at current collection on superficial layer.With resulting negative pole under 160 ℃ condition in 1 week of vacuum tank inner drying, make that the moisture containing ratio is 390ppm (embodiment 5).With resulting negative pole under 160 ℃ condition vacuum tank inner drying 3 hours, make that the moisture containing ratio is 870ppm (embodiment 6).
Other is with embodiment 5 and 6 phase regions, and the negative pole that comparative example 2 is obtained in 1 week of vacuum tank inner drying, makes that the moisture containing ratio is 390ppm (comparative example 3) under 160 ℃ condition.With resulting negative pole under 160 ℃ condition vacuum tank inner drying 3 hours, make the moisture containing ratio reach 870ppm (comparative example 4).
Use resulting negative pole to make battery, measure cycle characteristics.The result as shown in Figure 7 and Figure 8.In addition, the mensuration at embodiment 5 proceeds to 100 circulations.Other mensuration proceeds to 50 circulations.As battery to electrode, use on thickness is the Al paper tinsel of 20 μ m and be coated with LiCoO
2And the electrode of making.As nonaqueous electrolytic solution, use LiPF
6The mixed solution of/ethylene carbonate and dimethyl carbonate (volume ratio of 1:1).The condition that discharges and recharges is as described below.
Primary charging: constant current constant voltage pattern, current density 0.4mA/cm
2, end: 4.15V, 0.04mA/cm
2
The 2nd circulation charging afterwards: constant current mode, current density 1.0mA/cm
2, by 3.95V
First discharge: constant current constant voltage pattern, current density 0.4mA/cm
2, end: 2.7V
The 2nd circulation charging afterwards: constant current mode, current density 1.0mA/cm
2, end: 2.7V
As the result of Fig. 7 and Fig. 8 clearly illustrate, can judge that the negative pole of each embodiment is not observed the reduction of capacity yet after discharging and recharging repeatedly.In contrast, the negative pole of each comparative example causes capacity to reduce gradually along with discharging and recharging repeatedly.
[embodiment 7 and comparative example 5]
In present embodiment and comparative example, to by the difference of the amount of the oxygen that is comprised in the negative pole and the difference of the negative pole performance that causes estimate.By heat-treat negative pole (the moisture containing ratio the is 390ppm) oxidation that makes embodiment 5 obtain in atmosphere, oxygen concentration reaches 4000ppm (embodiment 7).In addition, after the further drying of the negative pole that comparative example 4 is obtained makes that the moisture containing ratio reaches 390ppm, make its oxidation by heat treatment in atmosphere, oxygen concentration reaches 4000ppm (comparative example 5).
The charge-discharge characteristic of the negative pole that embodiment 7 and comparative example 5 are obtained is estimated.The result is shown in Fig. 9 (a).Fig. 9 (b) is the enlarged drawing of rising part of the charging and discharging curve of Fig. 9 (a).By the result shown in Fig. 9 (a) and Fig. 9 (b), particularly as the result shown in Fig. 9 (b) know show, can judge, negative pole for comparative example 5, the peculiar acromion part of observing oxidized of negative pole, and in contrast, for the negative pole of embodiment 7, then this acromion has partly disappeared.Its reason is because the lithium metal that is comprised in the negative pole of embodiment 7 has been captured oxygen.
As above described in detail such, according to negative pole of the present invention,, also can supply with by dissolving lithium from the lithium metal layer even lithium has been consumed when discharging and recharging.Therefore, solved problem in the what is called " lithium exhaustion " of comparing with the amount (capacity) of negative electrode active material, being worried during battery design that the amount (capacity) of positive active material is less.Therefore, can reduce the initial stage irreversible capacity, and improve the efficiency for charge-discharge (cycle characteristics) of each charge and discharge cycles.In addition, because active material embeds lithium before discharging and recharging beginning, therefore can alleviate owing to embed the caused volume of lithium when discharging and recharging increases.This raising for cycle life also is contributive greatly.
In addition,, be consumed, thereby interior moisture and the oxygen of battery has reduced because this moisture and oxygen and lithium metal react even in the battery component parts that with the negative pole is representative, comprise under the moisture and the situation of oxygen of trace.Like this, also the initial stage irreversible capacity can be reduced, the efficiency for charge-discharge (cycle characteristics) of each charge and discharge cycles can also be improved simultaneously.
In addition, produce the space in the lithium metal layer after the lithium dissolving, the stress that expansion and contraction produced of the active material when discharging and recharging has been relaxed in this space, thereby can suppress the micronizing of active material.In addition, even carry out the micronizing of active material, because active material does not come out on the surface of electrode; but be embedded in the inside of electrode; thereby can prevent coming off of active material, even and discharge and recharge repeatedly, also can guarantee the current collection of active material.And, owing to lithium metal does not come out, but be positioned at its inside on the surface of negative pole, therefore can prevent the formation of the dendrite of lithium.
Claims (15)
1. negative electrode for nonaqueous secondary battery is characterized in that: comprise a pair of current collection usefulness superficial layer and active material layer and lithium metal layer between this a pair of current collection usefulness superficial layer.
2. according to the negative electrode for nonaqueous secondary battery of claim 1, it is characterized in that:
This negative pole comprises two negative pole precursors, and each negative pole precursor all comprises described current collection with superficial layer be arranged on this current collection lip-deep described active material layer with superficial layer,
The described lithium metal layer of clamping between described two negative pole precursors so that the described active material layer in each negative pole precursor each other mutually in the face of and described current collection with superficial layer outwardly.
3. according to the negative electrode for nonaqueous secondary battery of claim 1, it is characterized in that: at least one described current collection with forming a large amount of fine pores in the superficial layer, this fine pore described current collection with the surface of superficial layer on by perforate form, simultaneously to its thickness direction extension and can permeate nonaqueous electrolytic solution.
4. according to the negative electrode for nonaqueous secondary battery of claim 3, it is characterized in that: described fine-pored average perforated area is 0.1～50 μ m
2, and percent opening is 0.1～20%.
5. according to the negative electrode for nonaqueous secondary battery of claim 1, it is characterized in that: in described active material layer, lithium compound forms the whole zone that the low metal material of ability is penetrated into the thickness direction of this active material layer, and whole negative pole has the current collection function as a whole.
6. according to the negative electrode for nonaqueous secondary battery of claim 1, it is characterized in that: described active material layer is to comprise the conductive paste that lithium compound forms the high active material particle of ability by coating to make.
7. according to the negative electrode for nonaqueous secondary battery of claim 1, it is characterized in that: described active material layer is to constitute by form the thin layer that lithium compound that method forms forms the high active material of ability by film.
8. according to the negative electrode for nonaqueous secondary battery of claim 1, it is characterized in that: described current collection superficial layer forms by electroplating.
9. according to the negative electrode for nonaqueous secondary battery of claim 1, it is characterized in that: described current collection superficial layer is to form the low metal material of ability by lithium compound to make.
10. make the method for the negative electrode for nonaqueous secondary battery of claim 2, it is characterized in that:
On foils, form the current collection superficial layer by electroplating,
Form active material layer at this current collection on superficial layer, had the negative pole precursor of this current collection successively with superficial layer and this active material layer thereby on described foils, form,
The mode of facing mutually each other with the described active material layer of each negative pole precursor sandwiches metallic lithium foil between two negative pole precursors, and it is as a whole that this metallic lithium foil and two negative pole precursors are formed by applying, then,
Described foils is peeled off with each negative pole precursor and separated.
11. negative electrode for nonaqueous secondary battery is characterized in that:
This negative pole comprise by lithium compound form a pair of current collection that the low metal material of ability makes with superficial layer and at this a pair of current collection with the active material layer between superficial layer,
At at least one described current collection with forming a large amount of fine pores in the superficial layer, this fine pore described current collection with the surface of superficial layer on by perforate form, simultaneously to its thickness direction extension and can permeate nonaqueous electrolytic solution,
Described active material layer comprise embedded lithium, lithium compound forms the high active material particle of ability, and lithium compound forms the whole zone that the low metal material of ability is penetrated into the thickness direction of this active material layer in this active material layer,
And described negative pole does not have the conductive metal paper tinsel layer as core.
12. the negative electrode for nonaqueous secondary battery according to claim 11 is characterized in that: described fine-pored average perforated area is 0.1～50 μ m
2, and percent opening is 0.1～20%.
13. the negative electrode for nonaqueous secondary battery according to claim 11 is characterized in that: described current collection superficial layer forms by electroplating.
14. make the method for the negative electrode for nonaqueous secondary battery of claim 12, it is characterized in that:
On foils, form the current collection superficial layer by electroplating,
This current collection with superficial layer on coating comprise the conductive paste of active material particle and form active material layer, had the negative pole precursor of this current collection successively thereby on described foils, form with superficial layer and this active material layer,
The mode of facing mutually each other with the described active material layer of each negative pole precursor sandwiches metallic lithium foil between two negative pole precursors, and it is as a whole that this metallic lithium foil and two negative pole precursors are formed by applying,
Be heated to the temperature that is enough to cause the lithium thermal diffusion, make lithium be diffused into the described active material layer from described metallic lithium foil, then,
Described foils is peeled off with each negative pole precursor and separated.
15. negative electrode for nonaqueous secondary battery is characterized in that:
This negative pole comprise by lithium compound form a pair of current collection that the low metal material of ability makes with superficial layer and at this a pair of current collection with the active material layer between superficial layer,
At at least one described current collection with forming a large amount of fine pores in the superficial layer, this fine pore described current collection with the surface of superficial layer on by perforate form, simultaneously to its thickness direction extension and can permeate nonaqueous electrolytic solution,
Described active material layer comprise embedded lithium, lithium compound forms the high active material particle of ability, and lithium compound forms the whole zone that the low metal material of ability is penetrated into the thickness direction of this active material layer in this active material layer,
And described negative pole has the conductive metal paper tinsel layer as core between described a pair of current collection is with superficial layer.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP141981/2004 | 2004-05-12 | ||
| JP2004141981 | 2004-05-12 | ||
| JP061280/2005 | 2005-03-04 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1957489A CN1957489A (en) | 2007-05-02 |
| CN100524900C true CN100524900C (en) | 2009-08-05 |
Family
ID=38063770
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2005800150648A Expired - Fee Related CN100524900C (en) | 2004-05-12 | 2005-05-02 | Negative electrode for nonaqueous electrolyte secondary battery and process of producing the same |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100524900C (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107665978A (en) * | 2016-07-27 | 2018-02-06 | 现代自动车株式会社 | Electrode of lithium secondary cell, the manufacture method of electrode and the lithium secondary battery including the electrode |
Families Citing this family (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8206569B2 (en) | 2009-02-04 | 2012-06-26 | Applied Materials, Inc. | Porous three dimensional copper, tin, copper-tin, copper-tin-cobalt, and copper-tin-cobalt-titanium electrodes for batteries and ultra capacitors |
| KR101733134B1 (en) * | 2009-02-04 | 2017-05-08 | 어플라이드 머티어리얼스, 인코포레이티드 | Porous three dimensional copper, tin, copper-tin, copper-tin-cobalt, and copper-tin-cobalt-titanium electrodes for batteries and ultra capacitors |
| EP2638582A1 (en) * | 2010-11-09 | 2013-09-18 | 3M Innovative Properties Company | High capacity alloy anodes and lithium-ion electrochemical cells containing same |
| JP6495570B2 (en) * | 2012-03-23 | 2019-04-03 | 株式会社半導体エネルギー研究所 | Power storage device |
| CN103606644B (en) * | 2013-10-28 | 2017-01-04 | 珠海光宇电池有限公司 | The negative plate of lithium ion battery, barrier film and both manufacture methods |
| KR102040257B1 (en) * | 2016-09-13 | 2019-11-04 | 주식회사 엘지화학 | Method for manufacturing electrode |
| KR102439128B1 (en) * | 2018-07-06 | 2022-09-02 | 주식회사 엘지에너지솔루션 | Negative electrode for lithium secondary battery, prelithiation method thereof, and lithium secondary battery comprising the same |
| JP7100560B2 (en) * | 2018-10-29 | 2022-07-13 | Ｊｘ金属株式会社 | Lithium-ion battery Rolled copper foil for collector and lithium-ion battery |
| CN111224071B (en) * | 2018-11-27 | 2022-07-12 | 北京卫蓝新能源科技有限公司 | Preparation method and application of electrode with high cycle efficiency |
| CN109817953A (en) * | 2019-03-25 | 2019-05-28 | 湖北锂诺新能源科技有限公司 | Prelithiation silicon-carbon cathode material and preparation method thereof and lithium ion battery |
| CN110350202A (en) * | 2019-07-24 | 2019-10-18 | 江苏塔菲尔新能源科技股份有限公司 | A kind of collector and preparation method thereof and lithium ion battery |
| CN112825350B (en) * | 2019-11-20 | 2022-07-26 | 郑州宇通集团有限公司 | Pre-lithiation negative pole piece, preparation method thereof and lithium secondary battery |
| CN112201771A (en) * | 2020-10-14 | 2021-01-08 | 惠州亿纬锂能股份有限公司 | Pole piece, preparation method thereof and lithium ion battery |
-
2005
- 2005-05-02 CN CNB2005800150648A patent/CN100524900C/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107665978A (en) * | 2016-07-27 | 2018-02-06 | 现代自动车株式会社 | Electrode of lithium secondary cell, the manufacture method of electrode and the lithium secondary battery including the electrode |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1957489A (en) | 2007-05-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100524900C (en) | Negative electrode for nonaqueous electrolyte secondary battery and process of producing the same | |
| EP1750314B1 (en) | Negative electrode for nonaqueous electrolyte secondary battery and method for producing same | |
| US7838154B2 (en) | Negative electrode for nonaqueous secondary battery | |
| US7682739B2 (en) | Negative electrode for nonaqueous secondary battery and process of producing the same | |
| JP4024254B2 (en) | Non-aqueous electrolyte secondary battery | |
| CN100566006C (en) | The manufacture method of nonaqueous electrolytic solution secondary battery | |
| US20060063071A1 (en) | Electrode for secondary battery, process of producing the electrode, and secondary battery | |
| BR0317920B1 (en) | negative electrode for non-aqueous secondary battery, negative electrode production process, and non-aqueous secondary battery. | |
| TWI310994B (en) | Negative electrode for nonaqueous secondary battery | |
| RU2336603C2 (en) | Secondary storage battery electrode, method of its production and secondary storage battery | |
| JP4616584B2 (en) | Anode for non-aqueous electrolyte secondary battery | |
| CN100514716C (en) | Negative electrode for nonaqueous secondary battery | |
| KR100974402B1 (en) | Secondary battery-use electrode and production method therefor and secondary battery | |
| US20060147801A1 (en) | Electrode for secondary battery, process of producing the electrode, and secondary battery | |
| JP2005197217A (en) | Anode for non-aqueous electrolytic solution secondary battery | |
| JP3906342B2 (en) | Negative electrode for non-aqueous electrolyte secondary battery and method for producing the same | |
| WO2005108647A1 (en) | Porous metal foil with carrier foil and process for producing the same | |
| US20090191459A1 (en) | Electrode for nonaqueous electrolyte secondary battery | |
| JP2005129264A (en) | Porous metallic foil and its manufacturing method | |
| JP2006228512A (en) | Anode for nonaqueous electrolyte secondary battery | |
| JP3742828B2 (en) | Anode for non-aqueous electrolyte secondary battery | |
| JP2006134891A (en) | Negative electrode for nonaqueous electrolyte secondary battery |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20090805 Termination date: 20170502 |