JP6982779B2 - Manufacturing method of non-water-based secondary battery - Google Patents
Manufacturing method of non-water-based secondary battery Download PDFInfo
- Publication number
- JP6982779B2 JP6982779B2 JP2017086284A JP2017086284A JP6982779B2 JP 6982779 B2 JP6982779 B2 JP 6982779B2 JP 2017086284 A JP2017086284 A JP 2017086284A JP 2017086284 A JP2017086284 A JP 2017086284A JP 6982779 B2 JP6982779 B2 JP 6982779B2
- Authority
- JP
- Japan
- Prior art keywords
- positive electrode
- battery
- active material
- secondary battery
- mass
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Landscapes
- Battery Electrode And Active Subsutance (AREA)
Description
本発明は、非水系二次電池の製造方法に関する。 The present invention relates to a method for manufacturing a non-aqueous secondary battery.
非水系二次電池では、電池性能の向上を目的として、電池内に無機リン酸塩を含ませることがある(特許文献1,2参照)。例えば特許文献1には、所謂、5V級の正極に、所定の割合でリン酸三リチウム(Li3PO4)を含有させることにより、正極活物質からの遷移金属の溶出を防いで、電池の耐久性を向上し得る旨が開示されている。 In a non-aqueous secondary battery, an inorganic phosphate may be contained in the battery for the purpose of improving the battery performance (see Patent Documents 1 and 2). For example, in Patent Document 1, the so-called 5V class positive electrode contains trilithium phosphate (Li 3 PO 4 ) in a predetermined ratio to prevent the elution of the transition metal from the positive electrode active material, thereby preventing the elution of the transition metal from the positive electrode active material. It is disclosed that durability can be improved.
しかしながら、本発明者らの検討によれば、かかる電池では、正極中のLi3PO4の含有割合が同じであっても、生産技術上の問題が生じたり、得られた電池の性能がバラついたりする問題があった。具体的には、正極の作製時に正極集電体から正極合剤層が剥離し易くなったり、充放電時の電池抵抗がバラついたりすることがあった。そこで、本発明者らが鋭意検討を重ねたところ、正極にLi3PO4を含ませる場合、Li3PO4の含水量や正極作製時の乾燥温度の差異が上記問題の発生に大きく影響していることが判明した。 However, according to the study by the present inventors, in such a battery, even if the content ratio of Li 3 PO 4 in the positive electrode is the same, problems in production technology may occur or the performance of the obtained battery may vary. There was a problem with sticking. Specifically, the positive electrode mixture layer may be easily peeled off from the positive electrode current collector when the positive electrode is manufactured, or the battery resistance during charging / discharging may vary. Therefore, as a result of diligent studies by the present inventors, when Li 3 PO 4 is contained in the positive electrode, the difference in the water content of Li 3 PO 4 and the drying temperature at the time of producing the positive electrode greatly affects the occurrence of the above problem. It turned out that.
本発明は、かかる点に鑑みてなされたものであり、その目的は、Li3PO4を含む正極を備え、かつ低抵抗な非水系二次電池を安定的に製造することにある。 The present invention has been made in view of this point, and an object of the present invention is to stably manufacture a non-aqueous secondary battery having a positive electrode containing Li 3 PO 4 and having low resistance.
本発明により、正極活物質と、カールフィッシャー法(加熱温度:300℃)に基づく水分量が0.01質量%以上2.5質量%以下であるLi3PO4と、を含んだ正極ペーストを調製する工程;上記正極ペーストを正極集電体の上に付与して、110℃以上180℃以下の温度で乾燥させることにより、正極を作製する工程;上記正極と、負極と、非水電解質とを電池ケースに収容して、非水系二次電池を構築する工程;を包含する、非水系二次電池の製造方法が提供される。 According to the present invention, a positive electrode paste containing a positive electrode active material and Li 3 PO 4 having a water content of 0.01% by mass or more and 2.5% by mass or less based on the curl Fisher method (heating temperature: 300 ° C.) is prepared. Step of preparing; A step of producing a positive electrode by applying the positive electrode paste onto a positive electrode current collector and drying it at a temperature of 110 ° C. or higher and 180 ° C. or lower; the positive electrode, the negative electrode, and a non-aqueous electrolyte. Is provided in a battery case to construct a non-aqueous secondary battery; a method for manufacturing a non-aqueous secondary battery is provided.
正極ペーストに上記水分量のLi3PO4を含有させ、かつ、正極の乾燥温度を上記範囲とすることで、正極集電体から正極合剤層が剥離し難くなる。そのため、正極集電体と正極合剤層とが強固に一体化され、取扱性に優れた正極を作製することができる。また、上記製造方法によれば、例えば低SOC領域においても電池抵抗の低減された非水系二次電池を安定的に実現することができる。 By containing Li 3 PO 4 having the above-mentioned water content in the positive electrode paste and setting the drying temperature of the positive electrode within the above range, the positive electrode mixture layer is less likely to be peeled off from the positive electrode current collector. Therefore, the positive electrode current collector and the positive electrode mixture layer are firmly integrated, and a positive electrode having excellent handleability can be produced. Further, according to the above manufacturing method, a non-aqueous secondary battery with reduced battery resistance can be stably realized even in a low SOC region, for example.
なお、本明細書において、「カールフィッシャー法(加熱温度:300℃)に基づく水分量」とは、カールフィッシャー水分計を用いて水分気化法で測定した水分量をいう。具体的には、カールフィッシャー水分計に被測定物であるLi3PO4を1g投入し、300℃まで加熱したときに蒸発(気化)する水分を溶媒に捕集し、滴定法で測定した値をいう。 In the present specification, the "moisture content based on the curl fisher method (heating temperature: 300 ° C.)" means the water content measured by the water vaporization method using a curl fisher moisture meter. Specifically, 1 g of Li 3 PO 4 , which is the object to be measured, was put into a Karl Fischer moisture meter, and the moisture that evaporates (vaporizes) when heated to 300 ° C. is collected in a solvent, and the value measured by the titration method. To say.
また、本明細書において、「SOC(State of Charge:充電状態)」とは、電池が通常使用される電圧範囲を基準とする充電状態をいう。また、低SOC領域とは、SOCが概ね30%以下の領域、特には20%以下の領域を指すものとする。 Further, in the present specification, the “SOC (State of Charge)” refers to a state of charge based on the voltage range in which the battery is normally used. Further, the low SOC region refers to a region having an SOC of about 30% or less, particularly a region having an SOC of 20% or less.
以下、ここで開示される製造方法の好適な実施形態を説明する。なお、本明細書において特に言及している事項以外の事柄であって本発明の実施に必要な事柄は、当該分野における従来技術に基づく当業者の設計事項として把握され得る。本発明は、本明細書に開示されている内容と当該分野における技術常識とに基づいて実施することができる。
なお、本明細書において数値範囲をA〜B(ここでA,Bは任意の数値)と記載している場合は、A以上B以下を意味することとする。
Hereinafter, preferred embodiments of the manufacturing method disclosed herein will be described. Matters other than those specifically mentioned in the present specification and necessary for carrying out the present invention can be grasped as design matters of those skilled in the art based on the prior art in the art. The present invention can be carried out based on the contents disclosed in the present specification and the common general technical knowledge in the art.
In this specification, when the numerical range is described as A to B (where A and B are arbitrary numerical values), it means A or more and B or less.
本実施形態に係る非水系二次電池の製造方法は、次の3つの工程:(ステップS1)正極ペーストの調製工程;(ステップS2)正極ペーストの付与・乾燥工程;(ステップS3)電池の構築工程;を包含する。以下、各工程について詳細に説明する。 The method for manufacturing a non-aqueous secondary battery according to the present embodiment includes the following three steps: (step S1) positive electrode paste preparation step; (step S2) positive electrode paste application / drying step; (step S3) battery construction. Includes steps; Hereinafter, each step will be described in detail.
<(ステップS1)正極ペーストの調製工程>
本工程では、まず、少なくとも正極活物質とリン酸三リチウム(Li3PO4)と溶媒とを用意する。溶媒としては、例えば、NMP(N−メチル−2−ピロリドン)等の有機溶媒を用いることができる。
<(Step S1) Preparation step of positive electrode paste>
In this step, first, at least a positive electrode active material, trilithium phosphate (Li 3 PO 4 ), and a solvent are prepared. As the solvent, for example, an organic solvent such as NMP (N-methyl-2-pyrrolidone) can be used.
正極活物質は、電荷担体を可逆的に吸蔵及び放出可能な材料であればよい。正極活物質の好適例としては、リチウムニッケル含有複合酸化物、リチウムコバルト含有複合酸化物、リチウムニッケルコバルト含有複合酸化物、リチウムマンガン含有複合酸化物、リチウムニッケルコバルトマンガン含有複合酸化物等のリチウム遷移金属複合酸化物が挙げられる。高耐久の観点からは、通常使用時の作動電位が金属リチウム基準で4.2V以下である、所謂、4V級の正極活物質が好ましい。4V級の正極活物質の一好適例として、層状構造のリチウムニッケルコバルトマンガン含有複合酸化物が挙げられる。4V級の正極活物質を用いる場合、5V級の正極活物質を用いる場合に比べて、低SOC領域における正極の電位の低下度合いが大きく、電池抵抗が増大しやすい傾向にある。したがって、4V級の正極活物質を用いる場合、ここに開示される技術の効果がより良く発揮される。 The positive electrode active material may be any material that can reversibly occlude and release the charge carrier. Preferable examples of the positive electrode active material include lithium transition such as lithium nickel-containing composite oxide, lithium cobalt-containing composite oxide, lithium nickel cobalt-containing composite oxide, lithium manganese-containing composite oxide, and lithium nickel cobalt manganese-containing composite oxide. Examples include metal composite oxides. From the viewpoint of high durability, a so-called 4V class positive electrode active material having an operating potential during normal use of 4.2V or less based on metallic lithium is preferable. A preferred example of the 4V class positive electrode active material is a layered structure lithium nickel cobalt manganese-containing composite oxide. When a 4V class positive electrode active material is used, the degree of decrease in the potential of the positive electrode in the low SOC region is large and the battery resistance tends to increase as compared with the case where a 5V class positive electrode active material is used. Therefore, when a 4V class positive electrode active material is used, the effect of the technique disclosed herein is better exhibited.
正極活物質は、典型的には粒子状である。正極活物質の平均粒径(レーザー回折・光散乱法に基づく50体積%粒径(D50粒径)。以下同じ。)は、典型的には1〜20μm、例えば3〜10μm程度であるとよい。 The positive electrode active material is typically in the form of particles. The average particle size of the positive electrode active material (50 vol% particle diameter based on laser diffraction light scattering method (D 50 particle size). Hereinafter the same.) Are typically 1 to 20 [mu] m, for example, is about 3~10μm good.
正極活物質は、典型的には、カールフィッシャー法(加熱温度:300℃)に基づく水分量がLi3PO4よりも小さい。正極活物質の水分量は、例えば、0.01〜0.1質量%程度である。 The positive electrode active material typically has a water content smaller than that of Li 3 PO 4 based on the Karl Fischer method (heating temperature: 300 ° C.). The water content of the positive electrode active material is, for example, about 0.01 to 0.1% by mass.
Li3PO4は、例えば、以下の効果:(1)正極活物質の表面を被覆する;(2)非水電解質の酸化分解(典型的には、該非水電解質に含まれる支持塩の加水分解)を抑制する;(3)フッ素含有支持塩(例えばフッ素含有リチウム塩)の加水分解によって生成されるフッ酸(HF)を捕捉あるいは消費して、非水電解質の酸性度(pH)を緩和する;のうち少なくとも1つの効果を奏する。これらの効果によって、正極活物質からの金属元素の溶出が抑制され、電池の耐久性が向上する。また、過充電時には電池温度の上昇が抑えられ、過充電耐性が向上する。 Li 3 PO 4 has, for example, the following effects: (1) coating the surface of the positive electrode active material; (2) oxidative decomposition of the non-aqueous electrolyte (typically, hydrolysis of the supporting salt contained in the non-aqueous electrolyte). ); (3) Capturing or consuming hydrofluoric acid (HF) produced by hydrolysis of a fluorine-containing supporting salt (for example, a fluorine-containing lithium salt) to alleviate the acidity (pH) of the non-aqueous electrolyte. At least one of the effects; Due to these effects, elution of metal elements from the positive electrode active material is suppressed, and the durability of the battery is improved. In addition, the rise in battery temperature is suppressed during overcharging, and overcharging resistance is improved.
Li3PO4は、典型的には粒子状である。Li3PO4の平均粒径は、概ね0.1〜30μm、典型的には1〜25μm、例えば2〜10μm、好ましくは2〜5μm程度である。平均粒径を所定値以上とすることで、正極ペーストの取扱性を向上することができる。平均粒径を所定値以下とすることで、電池抵抗を低減して耐久性等の電池性能をより良く向上することができる。Li3PO4の平均粒径は、典型的には正極活物質の平均粒径と同等(±1μm程度)か、正極活物質の平均粒径よりも小さいことが好ましい。これにより、上述した効果をより良く発揮することができる。 Li 3 PO 4 is typically particulate. The average particle size of Li 3 PO 4 is approximately 0.1 to 30 μm, typically 1 to 25 μm, for example, 2 to 10 μm, preferably about 2 to 5 μm. By setting the average particle size to a predetermined value or more, the handleability of the positive electrode paste can be improved. By setting the average particle size to a predetermined value or less, the battery resistance can be reduced and the battery performance such as durability can be improved better. It is preferable that the average particle size of Li 3 PO 4 is typically the same as the average particle size of the positive electrode active material (about ± 1 μm) or smaller than the average particle size of the positive electrode active material. Thereby, the above-mentioned effect can be more exerted.
Li3PO4の比表面積(窒素ガスを用いた定容量式吸着法により測定した表面積をBET法で解析したBET比表面積。)は、典型的には0.5〜30m2/g、例えば1〜20m2/gであるとよい。 The specific surface area of Li 3 PO 4 (BET specific surface area obtained by analyzing the surface area measured by the constant volume adsorption method using nitrogen gas by the BET method) is typically 0.5 to 30 m 2 / g, for example, 1. It should be ~ 20 m 2 / g.
Li3PO4は、カールフィッシャー法(加熱温度:300℃)に基づく水分量が0.01〜2.5質量%である。加熱温度300℃で気化する水分には、Li3PO4の表面に物理的に吸着している付着水のみならず、例えば加熱温度200℃を超えて気化するような結晶水をも含まれる。水分量を0.01質量%以上とすることで、Li3PO4の結晶構造の安定性を向上することができ、Li3PO4の添加の効果が長期にわたって発揮される。かかる観点からは、Li3PO4のカールフィッシャー法(加熱温度:300℃)に基づく水分量が0.05質量%以上、典型的には1質量%以上、例えば2質量%以上であってもよい。また、水分量を2.5質量%以下とすることで、正極の抵抗を低減して、例えば低SOC領域においても電池抵抗の増大を好適に抑制することができる。 Li 3 PO 4 has a water content of 0.01 to 2.5% by mass based on the Karl Fischer method (heating temperature: 300 ° C.). The water vaporized at a heating temperature of 300 ° C. includes not only the adhering water physically adsorbed on the surface of Li 3 PO 4 , but also water of crystallization that vaporizes at a heating temperature of 200 ° C. or higher, for example. The water content by 0.01 mass% or more, it is possible to improve the stability of the crystal structure of Li 3 PO 4, the effect of addition of Li 3 PO 4 can be exhibited over a long term. From this point of view, even if the water content of Li 3 PO 4 based on the Karl Fischer method (heating temperature: 300 ° C.) is 0.05% by mass or more, typically 1% by mass or more, for example, 2% by mass or more. good. Further, by setting the water content to 2.5% by mass or less, the resistance of the positive electrode can be reduced, and the increase in battery resistance can be suitably suppressed even in a low SOC region, for example.
なお、ここでは、上記した正極活物質とLi3PO4と溶媒とに加えて、必要に応じてさらに任意成分を用意してもよい。任意成分の一例としては、例えば、導電助剤、結着剤(バインダ)、増粘剤、pH調整剤等が挙げられる。
導電助剤としては、例えば、カーボンブラック(典型的にはアセチレンブラック)、活性炭、黒鉛、炭素繊維等の炭素材料が好適である。結着剤としては、例えば、ポリフッ化ビニリデン(PVdF)等のハロゲン化ビニル樹脂や、ポリエチレンオキサイド(PEO)等のポリアルキレンオキサイドが好適である。増粘剤としては、例えば、カルボキシメチルセルロース(CMC)等のセルロース類が好適である。pH調整剤としては、例えば、リン酸等の酸性物質が好適である。
Here, in addition to the above-mentioned positive electrode active material, Li 3 PO 4, and a solvent, an optional component may be further prepared if necessary. Examples of the optional component include a conductive auxiliary agent, a binder, a thickener, a pH adjuster and the like.
As the conductive auxiliary agent, for example, carbon materials such as carbon black (typically acetylene black), activated carbon, graphite, and carbon fiber are suitable. As the binder, for example, a vinyl halide resin such as polyvinylidene fluoride (PVdF) and a polyalkylene oxide such as polyethylene oxide (PEO) are suitable. As the thickener, for example, celluloses such as carboxymethyl cellulose (CMC) are suitable. As the pH adjuster, for example, an acidic substance such as phosphoric acid is suitable.
本工程では、次に、用意したこれらを所定の割合で混合して、正極ペースト(スラリー、インクを包含する。)を調製する。材料の混合には、例えば、ボールミル、ジェットミル、ディスパ等の従来公知の撹拌・混合装置を用いることができる。正極ペーストの固形分率(NV)は特に限定されないが、溶媒の乾燥除去性を考慮して、典型的には70質量%以上、例えば70〜85質量%とするとよい。 In this step, next, these prepared are mixed at a predetermined ratio to prepare a positive electrode paste (including slurry and ink). For mixing the materials, for example, a conventionally known stirring / mixing device such as a ball mill, a jet mill, or a dispa can be used. The solid content (NV) of the positive electrode paste is not particularly limited, but is typically 70% by mass or more, for example, 70 to 85% by mass in consideration of the drying and removing property of the solvent.
正極ペーストの固形分全体(100質量%)に対する正極活物質の割合は、概ね50〜95質量%、例えば80〜90質量%とするとよい。正極ペーストの固形分全体に対するLi3PO4の割合は、概ね0.1〜20質量%、例えば0.5〜10質量%、好ましくは1〜10質量%とするとよい。Li3PO4の割合が所定値以上であると、Li3PO4の添加の効果をより良く発揮することができる。Li3PO4の割合が所定値以下であると、正極の抵抗をより良く低減することができる。 The ratio of the positive electrode active material to the total solid content (100% by mass) of the positive electrode paste may be approximately 50 to 95% by mass, for example, 80 to 90% by mass. The ratio of Li 3 PO 4 to the total solid content of the positive electrode paste is generally 0.1 to 20% by mass, for example, 0.5 to 10% by mass, preferably 1 to 10% by mass. When the ratio of Li 3 PO 4 is equal to or higher than a predetermined value, the effect of adding Li 3 PO 4 can be more exerted. When the ratio of Li 3 PO 4 is not more than a predetermined value, the resistance of the positive electrode can be better reduced.
<(ステップS2)正極ペーストの付与・乾燥工程>
本工程では、まず、正極集電体を用意して、上記ステップS1で調製した正極ペーストを正極集電体の上に付与する。正極集電体としては、導電性の良好な金属製のシート、例えばアルミニウム箔を用いることができる。正極ペーストの付与には、例えば、コンマコータ等の従来公知の塗布装置を用いることができる。
<(Step S2) Applying / drying step of positive electrode paste>
In this step, first, a positive electrode current collector is prepared, and the positive electrode paste prepared in step S1 is applied onto the positive electrode current collector. As the positive electrode current collector, a metal sheet having good conductivity, for example, aluminum foil can be used. For applying the positive electrode paste, for example, a conventionally known coating device such as a comma coater can be used.
本工程では、次に、正極ペーストの付着した正極集電体を所定の温度で乾燥させて、正極ペースト中から溶媒を除去する。本実施形態では、乾燥時の温度を110℃以上180℃以下とする。乾燥時の温度を110℃以上とすることで、Li3PO4の付着水を好適に蒸発させ、正極合剤層内から除去することができる。これにより、高抵抗な化合物(例えば、正極集電体としてのアルミニウム箔と水分との反応で生じる酸化アルミニウム)の生成が抑えられる。そのため、正極の抵抗を低減することができ、例えば低SOC領域においても電池抵抗の増大を抑制することができる。また、乾燥時の温度を180℃以下、例えば150℃以下とすることで、正極ペーストの乾燥後もLi3PO4の結晶水を適切に残存させることができ、Li3PO4の結晶構造を安定に維持することができる。さらに、正極集電体と正極合剤層との一体性を高めることができる。 In this step, next, the positive electrode current collector to which the positive electrode paste is attached is dried at a predetermined temperature to remove the solvent from the positive electrode paste. In the present embodiment, the drying temperature is 110 ° C. or higher and 180 ° C. or lower. By setting the drying temperature to 110 ° C. or higher, the adhering water of Li 3 PO 4 can be suitably evaporated and removed from the positive electrode mixture layer. This suppresses the formation of a highly resistant compound (for example, aluminum oxide generated by the reaction between the aluminum foil as a positive electrode current collector and water). Therefore, the resistance of the positive electrode can be reduced, and the increase in battery resistance can be suppressed even in a low SOC region, for example. Further, the temperature during drying 180 ° C. or less, for example, by a 0.99 ° C. or less, after drying the positive electrode paste can also be appropriately residual water of crystallization Li 3 PO 4, the crystal structure of Li 3 PO 4 Can be maintained stable. Further, the integrity between the positive electrode current collector and the positive electrode mixture layer can be enhanced.
なお、正極ペーストの乾燥は、1段階で行ってもよく、多段階で行ってもよい。例えば、110℃未満の第1の温度で予備乾燥した後に、110℃以上180℃以下の第2の温度で乾燥してもよい。あるいは、110℃以上180℃以下の温度範囲で、同じまたは異なる温度で、2回以上に分けて乾燥してもよい。乾燥時間は特に限定されないが、典型的には1秒〜24時間、例えば30秒〜10時間程度であるとよい。生産性の観点からは、乾燥時間を概ね1時間以下、例えば10分以下とすることが好ましい。また、正極ペーストの乾燥時には、大気圧よりも減圧状態、例えば10〜50kPaの状態としてもよい。
これにより、正極集電体上に正極合剤層を備えた正極を作製することができる。
The positive electrode paste may be dried in one step or in multiple steps. For example, after pre-drying at a first temperature of less than 110 ° C., it may be dried at a second temperature of 110 ° C. or higher and 180 ° C. or lower. Alternatively, it may be dried in two or more times at the same or different temperatures in the temperature range of 110 ° C. or higher and 180 ° C. or lower. The drying time is not particularly limited, but is typically about 1 second to 24 hours, for example, about 30 seconds to 10 hours. From the viewpoint of productivity, it is preferable that the drying time is about 1 hour or less, for example, 10 minutes or less. Further, when the positive electrode paste is dried, the pressure may be lower than the atmospheric pressure, for example, 10 to 50 kPa.
This makes it possible to produce a positive electrode having a positive electrode mixture layer on the positive electrode current collector.
<(ステップS3)電池の構築工程>
本工程では、上記ステップS2で作製した正極と、負極と、非水電解質とを電池ケースに収容して、電池を構築する。
好適な一実施形態では、まず、負極を用意する。負極は、従来と同様でよく特に限定されない。負極は、典型的には、負極集電体と、負極集電体上に固着された負極合剤層とを備えている。負極集電体としては、導電性の良好な金属製のシート、例えば銅箔が好適である。負極合剤層は、負極活物質を含んでいる。負極活物質としては、例えば、天然黒鉛、人造黒鉛、非晶質コート黒鉛等の炭素材料が好適である。
<(Step S3) Battery construction process>
In this step, the positive electrode, the negative electrode, and the non-aqueous electrolyte produced in step S2 are housed in a battery case to construct a battery.
In one preferred embodiment, first, a negative electrode is prepared. The negative electrode is the same as the conventional one and is not particularly limited. The negative electrode typically includes a negative electrode current collector and a negative electrode mixture layer fixed on the negative electrode current collector. As the negative electrode current collector, a metal sheet having good conductivity, for example, a copper foil is suitable. The negative electrode mixture layer contains a negative electrode active material. As the negative electrode active material, for example, a carbon material such as natural graphite, artificial graphite, or amorphous coated graphite is suitable.
次に、上記ステップS2で作製した正極と、上記用意した負極とを、絶縁した状態で積層し、電極体を作製する。正極と負極との絶縁には、例えば、ポリエチレン(PE)やポリプロピレン(PP)等の樹脂製のセパレータを好適に用いることができる。 Next, the positive electrode produced in step S2 and the negative electrode prepared above are laminated in an insulated state to produce an electrode body. For the insulation between the positive electrode and the negative electrode, for example, a resin separator such as polyethylene (PE) or polypropylene (PP) can be preferably used.
次に、非水電解質を用意する。非水電解質は、従来と同様でよく特に限定されない。非水電解質は、典型的には支持塩と非水溶媒とを含み、室温(25℃)で液体状態を示す非水電解液である。支持塩は、非水溶媒中で解離して電荷担体を生成する。支持塩としては、典型的にはリチウム塩、例えば、LiPF6、LiBF4等のフッ素含有リチウム塩を好適に用いることができる。非水溶媒としては、例えば、非フッ素またはフッ素化のカーボネートを好適に用いることができる。カーボネートの一好適例として、エチレンカーボネート(EC)、プロピレンカーボネート(PC)、モノフルオロエチレンカーボネート(FEC)等の環状カーボネートや、ジメチルカーボネート(DMC)、エチルメチルカーボネート(EMC)、メチル−2,2,2−トリフルオロエチルカーボネート(MTFEC)等の鎖状カーボネートが挙げられる。 Next, a non-aqueous electrolyte is prepared. The non-aqueous electrolyte is the same as the conventional one and is not particularly limited. The non-aqueous electrolyte is a non-aqueous electrolyte solution that typically contains a supporting salt and a non-aqueous solvent and exhibits a liquid state at room temperature (25 ° C.). The supporting salt dissociates in a non-aqueous solvent to form a charge carrier. As the supporting salt, typically a lithium salt, for example, a fluorine-containing lithium salt such as LiPF 6 or LiBF 4 can be preferably used. As the non-aqueous solvent, for example, non-fluorinated or fluorinated carbonate can be preferably used. As a preferable example of the carbonate, cyclic carbonates such as ethylene carbonate (EC), propylene carbonate (PC) and monofluoroethylene carbonate (FEC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC) and methyl-2,2 , 2-Trifluoroethyl carbonate (MTFEC) and other chain carbonates.
次に、上記作製した電極体と、上記用意した非水電解質とを、電池ケースに収容する。電池ケースの材質としては、比較的軽量な金属(例えば、アルミニウム)が好適である。
これにより、非水系二次電池を構築することができる。
Next, the prepared electrode body and the prepared non-aqueous electrolyte are housed in a battery case. As the material of the battery case, a relatively lightweight metal (for example, aluminum) is suitable.
This makes it possible to construct a non-aqueous secondary battery.
本実施形態の製造方法では、ステップS1において、水分量が0.01〜2.5質量%のLi3PO4を正極ペーストに含有させる。また、ステップS2において、正極ペーストを正極集電体の上に付与して、110〜180℃で乾燥させる。このことにより、正極集電体と正極合剤層とが強固に一体化された正極を安定的に作製することができる。また、正極内の導電性が向上して、低SOC領域においても電池の抵抗を低く抑えることができる。これらの効果が相俟って、ここに開示される製造方法によれば、低抵抗な非水系二次電池を安定的に実現することができる。 In the production method of the present embodiment, in step S1, Li 3 PO 4 having a water content of 0.01 to 2.5% by mass is contained in the positive electrode paste. Further, in step S2, the positive electrode paste is applied onto the positive electrode current collector and dried at 110 to 180 ° C. This makes it possible to stably produce a positive electrode in which the positive electrode current collector and the positive electrode mixture layer are firmly integrated. In addition, the conductivity in the positive electrode is improved, and the resistance of the battery can be suppressed low even in the low SOC region. Combined with these effects, according to the manufacturing method disclosed herein, a low-resistance non-aqueous secondary battery can be stably realized.
以上のように、本実施形態の製造方法で得られた非水系二次電池は、低SOCの状態においても電池抵抗が低減されていることにより、優れた入出力密度やハイレート耐性を発揮することができる。したがって、本実施形態の非水系二次電池は、低SOC領域でハイレート充放電を繰り返す使用態様が想定される用途で、例えば、プラグインハイブリッド自動車、ハイブリッド自動車、電気自動車等の車両に搭載されるモーター駆動のための動力源として、特に好ましく用いることができる。 As described above, the non-aqueous secondary battery obtained by the manufacturing method of the present embodiment exhibits excellent input / output density and high rate resistance because the battery resistance is reduced even in a low SOC state. Can be done. Therefore, the non-aqueous secondary battery of the present embodiment is installed in a vehicle such as a plug-in hybrid vehicle, a hybrid vehicle, or an electric vehicle in an application in which high-rate charging / discharging is repeated in a low SOC region. It can be particularly preferably used as a power source for driving a motor.
以下、本発明に関する試験例を説明するが、本発明をかかる具体例に示すものに限定することを意図したものではない。 Hereinafter, test examples relating to the present invention will be described, but the present invention is not intended to be limited to those shown in such specific examples.
本実施例では、水分量が異なる2種類のLi3PO4を用いて正極ペーストを調製し、それぞれ、正極ペーストの乾燥温度を50〜250℃の間で異ならせて、正極を作製した。そして、得られた正極を用いてリチウムイオン二次電電池を構築し、電池の性能を評価した。 In this example, a positive electrode paste was prepared using two types of Li 3 PO 4 having different water contents, and the drying temperature of the positive electrode paste was different between 50 and 250 ° C. to prepare a positive electrode. Then, a lithium ion secondary electric battery was constructed using the obtained positive electrode, and the performance of the battery was evaluated.
<正極の作製>
まず、正極活物質としてのリチウムニッケルコバルトマンガン含有複合酸化物(LiNi1/3Co1/3Mn1/3O2)と、カールフィッシャー法(加熱温度:300℃)に基づく水分量が2.5wt%または3.0wt%のリン酸三リチウム(LPO、Li3PO4)と、結着剤としてのポリフッ化ビニリデン(PVdF)と、導電助剤としてのアセチレンブラック(AB)と、有機溶媒としてのN−メチル−2−ピロリドン(NMP)とを混合して、正極ペーストを調製した。なお、このとき、正極ペーストに含まれる水分の比率は、正極活物質:リン酸三リチウム:その他(結着剤等)=3:75:12であった。
<Manufacturing of positive electrode>
First, the amount of water based on the lithium nickel cobalt manganese-containing composite oxide (LiNi 1/3 Co 1/3 Mn 1/3 O 2 ) as the positive electrode active material and the curl fisher method (heating temperature: 300 ° C.) is 2. 5 wt% or 3.0 wt% trilithium phosphate (LPO, Li 3 PO 4 ), polyvinylidene fluoride (PVdF) as a binder, acetylene black (AB) as a conductive aid, and as an organic solvent. N-Methyl-2-pyrrolidone (NMP) was mixed with N-methyl-2-pyrrolidone (NMP) to prepare a positive electrode paste. At this time, the ratio of water contained in the positive electrode paste was positive electrode active material: trilithium phosphate: other (binding agent, etc.) = 3: 75: 12.
次に、上記調製した正極ペーストを、正極集電体としてのアルミニウム箔の表面に塗布した後、50℃、70℃、90℃、110℃、130℃、150℃、180℃、200℃、250℃の温度で、それぞれ2〜240秒間加熱乾燥することにより、(LPOの水分量が異なる2種)×(乾燥温度が異なる9種類)=18種類の正極を作製した。 Next, the positive electrode paste prepared above is applied to the surface of the aluminum foil as the positive electrode current collector, and then 50 ° C, 70 ° C, 90 ° C, 110 ° C, 130 ° C, 150 ° C, 180 ° C, 200 ° C, 250. By heating and drying at a temperature of ° C. for 2 to 240 seconds each, (2 types having different LPO water content) x (9 types having different drying temperatures) = 18 types of positive electrodes were prepared.
<正極の剥離強度測定>
上記作製した正極を幅10mmの短冊状にカットし、正極合剤層を剥離強度試験用土台に貼り付けた。次に、正極集電体をオートグラフ精密万能試験機で引っ張り、剥離強度を測定した。そして、LPOの水分量を2.5wt%とし、かつ乾燥温度を150℃とした例の剥離強度を100%として、各例の剥離強度を相対値(剥離強度率)で示した。
<Measurement of peeling strength of positive electrode>
The positive electrode produced above was cut into strips having a width of 10 mm, and the positive electrode mixture layer was attached to a base for a peel strength test. Next, the positive electrode current collector was pulled by an autograph precision universal testing machine, and the peel strength was measured. Then, the peel strength of each example was shown as a relative value (peeling strength ratio), with the moisture content of the LPO being 2.5 wt% and the peeling strength of the example having a drying temperature of 150 ° C. being 100%.
図1には、横軸に正極ペーストの乾燥温度、縦軸に正極の剥離強度率を示している。図1に示すように、正極ペーストの乾燥温度を180℃以下とすることで、剥離強度率が高い正極、すなわち、正極集電体と正極合剤層とが強固に一体化された正極を安定的に作製することができた。 In FIG. 1, the horizontal axis shows the drying temperature of the positive electrode paste, and the vertical axis shows the peel strength rate of the positive electrode. As shown in FIG. 1, by setting the drying temperature of the positive electrode paste to 180 ° C. or lower, a positive electrode having a high peel strength rate, that is, a positive electrode in which a positive electrode current collector and a positive electrode mixture layer are firmly integrated is stabilized. I was able to make it.
<リチウムイオン二次電電池の構築>
上記作製した正極と、負極活物質としての天然黒鉛を含んだ負極とを、樹脂製のセパレータを介して積層し、電極体を作製した。また、非水電解液として、環状カーボネートと鎖状カーボネートとを含む混合溶媒中に、リチウム塩としてのLiPF6を1mol/Lの濃度となるように溶解させたものを用意した。
そして、上記電極体と上記非水電解液とを電池ケースに収容し、4V級のリチウムイオン二次電池(計18種類)を構築した。
<Construction of lithium-ion secondary battery>
The positive electrode produced above and the negative electrode containing natural graphite as a negative electrode active material were laminated via a resin separator to prepare an electrode body. Further, as a non-aqueous electrolytic solution, a solution prepared by dissolving LiPF 6 as a lithium salt in a mixed solvent containing a cyclic carbonate and a chain carbonate so as to have a concentration of 1 mol / L was prepared.
Then, the electrode body and the non-aqueous electrolytic solution were housed in a battery case to construct a 4V class lithium ion secondary battery (18 types in total).
<初期充放電>
次に、各リチウムイオン二次電池に対して、25℃の温度環境下で、以下の充放電操作:(i)電池電圧が4.1Vとなるまで0.2Cのレートで定電流充電した後、電流が0.01Cのレートになるまで定電圧充電する;(ii)電池電圧が3.0Vとなるまで0.2Cのレートで定電流放電した後、電流が0.01Cのレートになるまで定電圧放電する;を行った。
<Initial charge / discharge>
Next, each lithium ion secondary battery is charged and discharged under the temperature environment of 25 ° C. by the following charge / discharge operation: (i) After constant current charging at a rate of 0.2 C until the battery voltage reaches 4.1 V. , Constant voltage charge until current reaches 0.01C rate; (ii) Constant current discharge at 0.2C rate until battery voltage reaches 3.0V, then until current reaches 0.01C rate Constant voltage discharge; was performed.
<IV抵抗測定>
25℃の温度環境下で、上記作製したリチウムイオン二次電池をSOC20%の状態に調整した。次に、25℃の温度環境下で、この電池に対して10Cのレートで10秒間の定電流放電を行い、電圧降下量を測定した。次に、かかる電圧降下量を放電電流値で除して、IV抵抗を算出した。そして、LPOの水分量を2.5wt%とし、かつ乾燥温度を150℃とした例のIV抵抗を100%として、各例のIV抵抗を相対値(IV抵抗増加率)で示した。
<IV resistance measurement>
The lithium ion secondary battery produced above was adjusted to a SOC of 20% under a temperature environment of 25 ° C. Next, in a temperature environment of 25 ° C., the battery was subjected to constant current discharge at a rate of 10 C for 10 seconds, and the amount of voltage drop was measured. Next, the IV resistance was calculated by dividing the amount of such voltage drop by the discharge current value. Then, the IV resistance of each example was shown as a relative value (IV resistance increase rate), with the water content of the LPO being 2.5 wt% and the IV resistance of the example having a drying temperature of 150 ° C. being 100%.
図2には、横軸に正極ペーストの乾燥温度、縦軸に電池のIV抵抗増加率を示している。図2に示すように、正極ペーストの乾燥温度を110℃以上とすることで、SOC20%においても電池抵抗の増大を好適に抑制することができた。この理由としては、Li3PO4の付着水を好適に蒸発除去することができ、高抵抗な化合物(例えば、アルミニウム箔と水分との反応で生じる酸化アルミニウム)の生成が抑えられたことが考えられた。 In FIG. 2, the horizontal axis shows the drying temperature of the positive electrode paste, and the vertical axis shows the IV resistance increase rate of the battery. As shown in FIG. 2, by setting the drying temperature of the positive electrode paste to 110 ° C. or higher, an increase in battery resistance could be suitably suppressed even at an SOC of 20%. The reason for this is that the water adhering to Li 3 PO 4 can be suitably evaporated and removed, and the formation of a highly resistant compound (for example, aluminum oxide generated by the reaction between the aluminum foil and water) is suppressed. Was done.
以上、本発明を詳細に説明したが、上記実施形態および実施例は例示にすぎず、ここに開示される発明には上述の具体例を様々に変形、変更したものが含まれる。 Although the present invention has been described in detail above, the above-described embodiments and examples are merely examples, and the inventions disclosed herein include various modifications and modifications of the above-mentioned specific examples.
Claims (1)
前記正極ペーストを正極集電体の上に付与して、110℃以上180℃以下の温度で乾燥させることにより、正極を作製する工程、および、
前記正極と、負極と、非水電解質とを電池ケースに収容して、非水系二次電池を構築する工程、
を包含する、非水系二次電池の製造方法。 A step of preparing a positive electrode paste containing a positive electrode active material and Li 3 PO 4 having a water content of 2% by mass or more and 2.5% by mass or less based on the Karl Fischer method (heating temperature: 300 ° C.).
A step of producing a positive electrode by applying the positive electrode paste onto a positive electrode current collector and drying it at a temperature of 110 ° C. or higher and 180 ° C. or lower, and
A step of accommodating the positive electrode, the negative electrode, and the non-aqueous electrolyte in a battery case to construct a non-aqueous secondary battery.
A method for manufacturing a non-aqueous secondary battery.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2017086284A JP6982779B2 (en) | 2017-04-25 | 2017-04-25 | Manufacturing method of non-water-based secondary battery |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2017086284A JP6982779B2 (en) | 2017-04-25 | 2017-04-25 | Manufacturing method of non-water-based secondary battery |
Publications (2)
Publication Number | Publication Date |
---|---|
JP2018185936A JP2018185936A (en) | 2018-11-22 |
JP6982779B2 true JP6982779B2 (en) | 2021-12-17 |
Family
ID=64357132
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2017086284A Active JP6982779B2 (en) | 2017-04-25 | 2017-04-25 | Manufacturing method of non-water-based secondary battery |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP6982779B2 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN110200310A (en) * | 2019-03-20 | 2019-09-06 | 福建绿色黄金生物科技有限公司 | It is a kind of for the oolong tea of electronic cigarette and the composition of lemon and its application |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3358478B2 (en) * | 1996-09-24 | 2002-12-16 | 新神戸電機株式会社 | Organic electrolyte secondary battery |
JP5115781B2 (en) * | 2006-10-23 | 2013-01-09 | トヨタ自動車株式会社 | Lithium secondary battery and manufacturing method thereof |
JP4843582B2 (en) * | 2007-08-17 | 2011-12-21 | 株式会社アルバック | Method for producing lithium phosphate sintered body and sputtering target |
JP2013048013A (en) * | 2009-12-17 | 2013-03-07 | Hitachi Vehicle Energy Ltd | Nonaqueous electrolyte secondary battery |
CN103262305B (en) * | 2010-12-14 | 2015-11-25 | 协立化学产业株式会社 | Battery electrode or baffle surface protective agent composition, by battery electrode of its protection or dividing plate and the battery with this battery electrode or dividing plate |
TWI611032B (en) * | 2013-09-05 | 2018-01-11 | 攀時歐洲公司 | Conductive target material |
JP2015090859A (en) * | 2013-11-07 | 2015-05-11 | 旭化成株式会社 | Nonaqueous electrolyte secondary battery |
JP6374650B2 (en) * | 2013-11-07 | 2018-08-15 | 旭化成株式会社 | Nonaqueous electrolyte secondary battery |
JP6137088B2 (en) * | 2014-08-29 | 2017-05-31 | トヨタ自動車株式会社 | Method for producing positive electrode active material layer for lithium ion battery, and positive electrode active material layer for lithium ion battery |
JP6083425B2 (en) * | 2014-10-17 | 2017-02-22 | トヨタ自動車株式会社 | Positive electrode mixture paste, positive electrode, non-aqueous electrolyte secondary battery, and non-aqueous electrolyte secondary battery manufacturing method |
-
2017
- 2017-04-25 JP JP2017086284A patent/JP6982779B2/en active Active
Also Published As
Publication number | Publication date |
---|---|
JP2018185936A (en) | 2018-11-22 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP3096379B1 (en) | Negative electrode material for nonaqueous electrolyte secondary batteries and method for producing negative electrode active material particles | |
TWI637550B (en) | Negative electrode material for non-aqueous electrolyte battery and method for producing negative electrode active material particles | |
WO2015198511A1 (en) | Negative electrode material for nonaqueous electrolyte secondary batteries, negative electrode for nonaqueous electrolyte secondary batteries, nonaqueous electrolyte secondary battery and method for producing negative electrode active material particles | |
KR20130086077A (en) | Negative electrode active material for lithium ion secondary battery | |
JP5783029B2 (en) | Negative electrode for non-aqueous electrolyte secondary battery, method for producing the same, and non-aqueous electrolyte secondary battery | |
JP2015162356A (en) | Coated positive electrode active material, method for producing coated positive electrode active material, and lithium battery | |
JP2002260634A (en) | Lithium secondary battery | |
JP6902206B2 (en) | Lithium ion secondary battery | |
JPWO2020049843A1 (en) | Coated positive electrode active material, manufacturing method of lithium ion secondary battery and lithium ion secondary battery | |
JP6627708B2 (en) | Lithium ion secondary battery and method of manufacturing lithium ion secondary battery | |
JP2019040721A (en) | Lithium ion secondary battery | |
JP5679206B2 (en) | Method for producing negative electrode for lithium ion secondary battery and method for producing lithium ion secondary battery | |
JP6982779B2 (en) | Manufacturing method of non-water-based secondary battery | |
KR102520421B1 (en) | Negative electrode | |
JP6905671B2 (en) | Manufacturing method of positive electrode for non-aqueous electrolyte lithium secondary battery | |
JP2013118104A (en) | Method for manufacturing negative electrode for nonaqueous electrolyte secondary battery, and method for manufacturing nonaqueous electrolyte secondary battery including the negative electrode | |
JP6895078B2 (en) | Lithium ion secondary battery | |
JP6895083B2 (en) | Non-aqueous secondary battery | |
JP6810897B2 (en) | Manufacturing method of non-aqueous electrolyte secondary battery | |
JP6883265B2 (en) | Lithium secondary battery | |
JP6864849B2 (en) | Negative electrode for non-aqueous electrolyte secondary battery | |
JP2016177962A (en) | Method for manufacturing secondary battery | |
JP2021077531A (en) | Non-aqueous electrolyte secondary battery | |
JP6323723B2 (en) | Non-aqueous electrolyte secondary battery manufacturing method and battery assembly | |
JP7361066B2 (en) | Graphite-based negative electrode active material and method for producing the graphite-based negative electrode active material |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20191028 |
|
A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20200626 |
|
A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20201126 |
|
A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20210624 |
|
A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20210922 |
|
C60 | Trial request (containing other claim documents, opposition documents) |
Free format text: JAPANESE INTERMEDIATE CODE: C60 Effective date: 20210922 |
|
A911 | Transfer to examiner for re-examination before appeal (zenchi) |
Free format text: JAPANESE INTERMEDIATE CODE: A911 Effective date: 20210929 |
|
C21 | Notice of transfer of a case for reconsideration by examiners before appeal proceedings |
Free format text: JAPANESE INTERMEDIATE CODE: C21 Effective date: 20210930 |
|
TRDD | Decision of grant or rejection written | ||
A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20211021 |
|
A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20211103 |
|
R151 | Written notification of patent or utility model registration |
Ref document number: 6982779 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R151 |