JP2013134863A - Negative electrode for secondary battery, method for manufacturing the same, and secondary battery - Google Patents
Negative electrode for secondary battery, method for manufacturing the same, and secondary battery Download PDFInfo
- Publication number
- JP2013134863A JP2013134863A JP2011283679A JP2011283679A JP2013134863A JP 2013134863 A JP2013134863 A JP 2013134863A JP 2011283679 A JP2011283679 A JP 2011283679A JP 2011283679 A JP2011283679 A JP 2011283679A JP 2013134863 A JP2013134863 A JP 2013134863A
- Authority
- JP
- Japan
- Prior art keywords
- active material
- secondary battery
- negative electrode
- current collector
- 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.)
- Granted
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
- Cell Electrode Carriers And Collectors (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
Description
本発明は、高容量、高出力を得られる負極およびその製法ならびに二次電池に関するものである。 The present invention relates to a negative electrode capable of obtaining high capacity and high output, a method for producing the same, and a secondary battery.
二次電池は携帯電話やノートＰＣ等の携帯用電子機器に多く使用されており、これらの機器の小型軽量化に伴い、よりエネルギー密度の高い二次電池が求められている。 Secondary batteries are often used in portable electronic devices such as mobile phones and notebook PCs. As these devices become smaller and lighter, secondary batteries with higher energy density are required.
従来より、これらの二次電池に負極活物質として用いられている黒鉛などの炭素材料は、単位体積あたりの容量が充分ではなく、更なるエネルギー密度の向上が困難であるため、炭素材料よりも容量が高く、エネルギー密度の向上が期待できる種々の負極活物質を用いることが検討されている。 Conventionally, carbon materials such as graphite used as a negative electrode active material in these secondary batteries have insufficient capacity per unit volume, and it is difficult to further improve energy density. The use of various negative electrode active materials that have a high capacity and can be expected to improve energy density has been studied.
高容量の負極活物質としては、Ｓｉ、Ａｌ、ＳｎなどのＬｉと合金を形成する金属およびその化合物が知られているが、充放電による体積変化が大きくサイクル特性に劣るため、たとえば特許文献１では、ケイ素を含む活物質を、加熱処理により非晶質炭素となるバインダとともに集電体上に塗布し、非酸化雰囲気下で焼結、一体化させることで、サイクル特性を向上させる非水系二次電池用負極の製造方法を提案している。 As high-capacity negative electrode active materials, metals that form alloys with Li, such as Si, Al, and Sn, and compounds thereof are known. However, since volume change due to charge and discharge is large and cycle characteristics are poor, for example, Patent Document 1 Then, an active material containing silicon is applied onto a current collector together with a binder that becomes amorphous carbon by heat treatment, and is sintered and integrated in a non-oxidizing atmosphere, thereby improving cycle characteristics. The manufacturing method of the negative electrode for secondary batteries is proposed.
しかしながら、特許文献１に記載されている負極の製造方法では、集電体である銅箔と活物質中のケイ素とが焼成中に反応し、リチウムイオンを吸蔵・放出しないケイ化銅（Ｃｕ３Ｓｉ）が多量に生成して活物質の充放電容量が低下したり、充放電時の活物質の体積変化により集電体が破壊されるという課題があった。 However, in the method for producing a negative electrode described in Patent Document 1, copper silicide (Cu 3) that does not occlude / release lithium ions reacts between the copper foil as a current collector and silicon in the active material during firing. There is a problem that a large amount of Si) is generated to reduce the charge / discharge capacity of the active material, or the current collector is destroyed due to a volume change of the active material during charge / discharge.
本発明は、このような実情に鑑みて提案されたものであり、その目的は高容量でサイクル特性に優れた二次電池用負極およびその製法ならびに二次電池を提供することである。 The present invention has been proposed in view of such circumstances, and an object of the present invention is to provide a secondary battery negative electrode having a high capacity and excellent cycle characteristics, a method for producing the same, and a secondary battery.
本発明の二次電池用負極は、活物質の粒子と炭素質材料とを含む焼結体である活物質層と、導電性材料を含む集電体とを備え、前記活物質がＳｉまたはＳｉを含む化合物であるとともに、前記活物質層と前記集電体との間に、炭素質材料からなる介在層を設けたことを特徴とする。 A negative electrode for a secondary battery according to the present invention includes an active material layer that is a sintered body including particles of an active material and a carbonaceous material, and a current collector including a conductive material, and the active material is Si or Si And an intervening layer made of a carbonaceous material is provided between the active material layer and the current collector.
本発明の二次電池用負極の製法は、導電性材料を含む集電体の表面に、炭素質材料または熱処理により炭化して炭素質材料となる材料を含む介在層前駆体被膜を形成する工程と、前記介在層前駆体被膜上に、ＳｉまたはＳｉを含む化合物の原料粉末と、炭素質材料または熱処理により炭化して炭素質材料となる材料と、を含む活物質層前駆体を形成する工程と、前記介在層前駆体被膜および前記活物質層前駆体を形成した前記集電体を、非酸化性雰囲気中で焼成する工程と、を有することを特徴とする。 The method for producing a negative electrode for a secondary battery according to the present invention includes a step of forming, on the surface of a current collector containing a conductive material, an intervening layer precursor coating containing a carbonaceous material or a material that is carbonized by heat treatment to become a carbonaceous material. And forming an active material layer precursor containing, on the intervening layer precursor coating, a raw material powder of Si or a compound containing Si, and a carbonaceous material or a material that is carbonized by heat treatment to become a carbonaceous material. And firing the current collector on which the intermediate layer precursor coating and the active material layer precursor are formed in a non-oxidizing atmosphere.
本発明の二次電池は、正極と、非水電解質と、前記二次電池用負極とを備えることを特
徴とする。
The secondary battery of the present invention includes a positive electrode, a nonaqueous electrolyte, and the negative electrode for a secondary battery.
本発明によれば、高容量でサイクル特性に優れた二次電池用負極およびその製法ならびに二次電池を提供することができる。 ADVANTAGE OF THE INVENTION According to this invention, the negative electrode for secondary batteries excellent in cycling characteristics with the high capacity | capacitance, its manufacturing method, and a secondary battery can be provided.
本発明の一実施形態である二次電池用負極を図１に基づいて説明する。本実施形態の二次電池用負極（以下、単に負極ともいう）は、活物質層１と集電体３との間に介在層２が設けられ、これらが一体となった構造を有する。活物質層１は、ＳｉまたはＳｉを含む化合物である活物質の粒子１ａと、炭素質材料１ｂとを含む焼結体であり、気孔１ｃを有していてもよい。また、必要に応じ、活物質の粒子１ａに含まれるＳｉと反応し難い導電助剤として、例えば金や白金等を含んでいてもよい。 A negative electrode for a secondary battery according to an embodiment of the present invention will be described with reference to FIG. The negative electrode for a secondary battery (hereinafter also simply referred to as a negative electrode) of the present embodiment has a structure in which an intervening layer 2 is provided between an active material layer 1 and a current collector 3 and these are integrated. The active material layer 1 is a sintered body including particles 1a of active material, which is Si or a compound containing Si, and a carbonaceous material 1b, and may have pores 1c. Further, as necessary, for example, gold or platinum may be included as a conductive aid that hardly reacts with Si contained in the active material particles 1a.
活物質の粒子１ａとして用いるＳｉおよびＳｉを含む化合物は、結晶質、非晶質のいずれでもよく、Ｓｉを含む化合物としては、たとえばＳｉとＣを含む化合物や、Ｌｉ、Ｔｉ、Ｌａ、Ｆｅ、Ｖ、Ｃｒ、Ｎｉ、Ｎｂ、Ｍｇ、Ｓｎ、Ｇｅ、Ａｌ、Ａｇ、Ｉｎ、ＧａおよびＳｂからなる金属群から選ばれる少なくとも１種の金属元素とＳｉとの合金などが挙げられる。Ｓｉと合金化する金属のうち、特にＴｉ、ＬａおよびＮｉは、高容量かつ比較的優れたサイクル特性が得られる点で好ましい。活物質の粒子１ａの平均粒子径は、充放電による体積変化の影響を低減しサイクル特性を向上できるという点から、５μｍ以下であることが好ましく、１μｍ以下であることがより好ましい。 The compound containing Si and Si used as the active material particles 1a may be crystalline or amorphous. Examples of the compound containing Si include a compound containing Si and C, Li, Ti, La, Fe, An alloy of at least one metal element selected from the metal group consisting of V, Cr, Ni, Nb, Mg, Sn, Ge, Al, Ag, In, Ga, and Sb and Si may be used. Of the metals alloyed with Si, Ti, La, and Ni are particularly preferable because they have a high capacity and relatively excellent cycle characteristics. The average particle diameter of the active material particles 1a is preferably 5 μm or less, more preferably 1 μm or less, from the viewpoint that the effect of volume change due to charge / discharge can be reduced and cycle characteristics can be improved.
炭素質材料１ｂとしては、黒鉛、難黒鉛化性炭素、ガラス状炭素およびこれらの混合物が挙げられ、電極容量の観点から、Ｌｉ吸蔵性のある黒鉛や難黒鉛化性炭素を用いることが好ましい。 Examples of the carbonaceous material 1b include graphite, non-graphitizable carbon, glassy carbon, and mixtures thereof. From the viewpoint of electrode capacity, it is preferable to use Li occluded graphite or non-graphitizable carbon.
活物質の種類は、Ｘ線回折（ＸＲＤ）測定や、波長分散型Ｘ線分析（ＷＤＳ）、ＩＣＰ分析等の元素分析法により確認できる。また、炭素質材料についてはラマン分光法により確認できる。 The type of active material can be confirmed by elemental analysis methods such as X-ray diffraction (XRD) measurement, wavelength dispersion X-ray analysis (WDS), and ICP analysis. Carbonaceous materials can be confirmed by Raman spectroscopy.
活物質層１中における活物質の粒子１ａの体積比率は、高容量の負極とするために２０体積％以上であることが好ましく、充放電時の体積変化による劣化を抑制するという点から７０体積％以下であることが好ましい。また、炭素質材料１ｂの体積比率は、電子伝導性の確保および活物質層の骨格構造の維持を担うという点から１０体積％以上であることが好ましく、活物質層１の負極としての容量を確保するという点から６０体積％以下であることが好ましい。活物質層１中における各構成要素の体積比率は、たとえば活物質層１の断面を走査電子顕微鏡（ＳＥＭ）と波長分散型Ｘ線分析（ＷＤＳ）により活物質の粒子を判別し、撮影した写真を画像解析して算出したり、ＩＣＰ分析や炭素分析（加熱分解して発生した炭素成分を定量する手法）による組成分析結果と各構成要素の比重とから計算するなどして確認すればよい。 The volume ratio of the active material particles 1a in the active material layer 1 is preferably 20% by volume or more in order to obtain a high-capacity negative electrode. % Or less is preferable. The volume ratio of the carbonaceous material 1b is preferably 10% by volume or more from the viewpoint of ensuring the electron conductivity and maintaining the skeletal structure of the active material layer. From the viewpoint of securing, it is preferably 60% by volume or less. The volume ratio of each component in the active material layer 1 is, for example, a photograph of a cross section of the active material layer 1 which is obtained by discriminating active material particles by scanning electron microscope (SEM) and wavelength dispersive X-ray analysis (WDS). May be calculated by image analysis or calculated from the composition analysis result by ICP analysis or carbon analysis (a method for quantifying the carbon component generated by thermal decomposition) and the specific gravity of each component.
活物質層１の厚さは、負極としての容量の確保や内部抵抗の低減という点から、１０μｍ〜２００μｍの範囲であることが好ましい。 The thickness of the active material layer 1 is preferably in the range of 10 μm to 200 μm from the viewpoint of securing capacity as a negative electrode and reducing internal resistance.
活物質層１は、活物質の粒子１ａの体積変化による応力の緩和や、電解質として有機電解液を用いた場合に活物質層１内部への有機電解液の浸透を促進するため、気孔を有して
いることが好ましい。活物質層１の気孔率は、応力緩和と電解液の浸透という点から１０％以上であることが好ましく、負極としての容量の確保や、電極強度の維持という点から６０％以下であることが好ましい。活物質層１の気孔率は、たとえば活物質層１の断面の走査電子顕微鏡（ＳＥＭ）写真を撮影し、画像解析することにより確認できる。
The active material layer 1 has pores to relieve stress due to volume change of the active material particles 1a and to promote the penetration of the organic electrolyte into the active material layer 1 when an organic electrolyte is used as the electrolyte. It is preferable. The porosity of the active material layer 1 is preferably 10% or more from the viewpoint of stress relaxation and electrolyte penetration, and it is preferably 60% or less from the viewpoint of securing capacity as a negative electrode and maintaining electrode strength. preferable. The porosity of the active material layer 1 can be confirmed, for example, by taking a scanning electron microscope (SEM) photograph of a cross section of the active material layer 1 and analyzing the image.
集電体３としては、導電性材料を含むもの、たとえば導電性フィラーを含むシートや接着剤、導電性の金属箔や金属メッシュ等が用いられる。導電性フィラーとしては、金属材料（アルミニウム、金、白金など）や導電性酸化物材料（酸化インジウムスズ（ＩＴＯ）ガラス、酸化スズなど）が挙げられる。また、金属箔や金属メッシュ等の材料としては、ステンレス、銅、金、白金などが使用できるが、導電性が高く比較的安価な点から銅を用いることが好ましい。特に、導電性の金属箔や金属メッシュは耐熱性が高く、これらを集電体３として用いた場合、活物質層１および介在層２との同時焼成が可能であるため好ましい。集電体３の厚みは５〜２０μｍとすればよい。 As the current collector 3, a material containing a conductive material, for example, a sheet or adhesive containing a conductive filler, a conductive metal foil, a metal mesh, or the like is used. Examples of the conductive filler include metal materials (aluminum, gold, platinum, etc.) and conductive oxide materials (indium tin oxide (ITO) glass, tin oxide, etc.). In addition, as a material such as a metal foil or a metal mesh, stainless steel, copper, gold, platinum, or the like can be used. However, it is preferable to use copper from the viewpoint of high conductivity and relatively low cost. In particular, conductive metal foils and metal meshes are preferable because they have high heat resistance, and when these are used as the current collector 3, they can be fired simultaneously with the active material layer 1 and the intervening layer 2. The thickness of the current collector 3 may be 5 to 20 μm.
なお、金属箔を使用する場合は、介在層２との接着力向上のために、金属箔の表面を粗面化処理したものを用いてもよい。この場合、金属箔の表面粗さは、算術平均粗さ（Ｒａ）にして０．５〜２μｍであることが好ましい。金属箔の表面粗さは、触針式、光干渉式等の表面粗さ計や、レーザー顕微鏡、原子間力顕微鏡（ＡＦＭ）等を用いて測定する。一般的に使用される触針式表面粗さ計を用いる場合は、ＪＩＳ Ｂ０６０１に基づいて、たとえば、触針先端径を２μｍ、測定長を４．８ｍｍ、カットオフ値を０．８ｍｍという条件で測定すればよい。 In addition, when using metal foil, in order to improve the adhesive force with the intervening layer 2, you may use what roughened the surface of metal foil. In this case, the surface roughness of the metal foil is preferably 0.5 to 2 μm in terms of arithmetic average roughness (Ra). The surface roughness of the metal foil is measured using a surface roughness meter such as a stylus type or a light interference type, a laser microscope, an atomic force microscope (AFM), or the like. When using a stylus-type surface roughness meter that is generally used, based on JIS B0601, for example, on the condition that the stylus tip diameter is 2 μm, the measurement length is 4.8 mm, and the cutoff value is 0.8 mm Just measure.
介在層２は、集電体３に接しているとともに、活物質の粒子１ａを含まない炭素質材料より構成される層であり、活物質の粒子１ａと集電体３との間に炭素質材料からなる介在層２を設けることにより、活物質の粒子１ａ内のＳｉと、集電体３に含まれる導電性材料中の金属元素との相互拡散および反応を抑制し、活物質層１中での容量の小さい反応生成物の生成を低減することができる。また集電体３に活物質の粒子１ａ中のＳｉ元素が拡散した場合、集電体３に含まれる導電性材料中の金属元素と、拡散したＳｉ元素とが反応し、集電体３の導電率の低下や強度の低下を引き起こすことがある。このような集電体３へのＳｉ元素の拡散も、介在層２により抑制することができる。 The intervening layer 2 is a layer made of a carbonaceous material that is in contact with the current collector 3 and does not include the active material particles 1 a, and the carbonaceous material is interposed between the active material particles 1 a and the current collector 3. By providing the intervening layer 2 made of a material, the interdiffusion and reaction between Si in the active material particles 1a and the metal element in the conductive material contained in the current collector 3 are suppressed, and the active material layer 1 It is possible to reduce the production of a reaction product with a small volume at. When the Si element in the active material particle 1 a diffuses into the current collector 3, the metal element in the conductive material contained in the current collector 3 reacts with the diffused Si element, and the current collector 3 It may cause a decrease in conductivity and a decrease in strength. Such diffusion of the Si element into the current collector 3 can also be suppressed by the intervening layer 2.
特に集電体３として、銅箔や、導電性材料に銅を含むものを用いた場合には、活物質の粒子１ａ中のＳｉと集電体３中のＣｕとが相互に拡散・反応して、活物質層１中にリチウムイオンを吸蔵・放出しないケイ化銅（Ｃｕ３Ｓｉ）を形成しやすく、活物質層１と集電体３との間に介在層２を設ける効果が特に顕著となる。 In particular, when the current collector 3 is a copper foil or a conductive material containing copper, Si in the active material particles 1a and Cu in the current collector 3 diffuse and react with each other. Thus, it is easy to form copper silicide (Cu 3 Si) that does not occlude / release lithium ions in the active material layer 1, and the effect of providing the intervening layer 2 between the active material layer 1 and the current collector 3 is particularly remarkable. It becomes.
介在層２を形成する炭素質材料としては、黒鉛、難黒鉛化性炭素、ガラス状炭素およびこれらの混合物が挙げられ、電極容量の観点から、Ｌｉ吸蔵性のある黒鉛や難黒鉛化炭素を用いることが好ましい。 Examples of the carbonaceous material forming the intervening layer 2 include graphite, non-graphitizable carbon, glassy carbon, and a mixture thereof. From the viewpoint of electrode capacity, graphite having Li occlusion and non-graphitizable carbon are used. It is preferable.
介在層２は、気孔２ｃを有していてもよく、これにより活物質の粒子１ａの体積変化に起因する活物質層１の体積変化による集電体３への応力負荷を緩和することができる。介在層２の気孔率は、１０％以上とすることが好ましい。また、活物質の粒子１ａ内のＳｉと、集電体２に含まれる導電性材料中の金属元素との相互拡散および反応の抑制機能を維持するという点から、介在層２の気孔率は５０％以下であることが好ましい。介在層２の気孔率は、たとえば負極の断面の走査電子顕微鏡（ＳＥＭ）写真を撮影し、介在層２の領域を画像解析することにより確認できる。 The intervening layer 2 may have pores 2 c, whereby the stress load on the current collector 3 due to the volume change of the active material layer 1 due to the volume change of the active material particles 1 a can be reduced. . The porosity of the intervening layer 2 is preferably 10% or more. In addition, the porosity of the intervening layer 2 is 50 in terms of maintaining the function of suppressing mutual diffusion and reaction between Si in the active material particles 1a and the metal elements in the conductive material contained in the current collector 2. % Or less is preferable. The porosity of the intervening layer 2 can be confirmed, for example, by taking a scanning electron microscope (SEM) photograph of a cross section of the negative electrode and analyzing the region of the intervening layer 2.
介在層２の厚さは、３μｍ以上、特に３〜１５μｍであることが好ましい。介在層２の厚さが３μｍ未満である場合は、活物質の粒子１ａ内のＳｉと、集電体３に含まれる導電
性材料中の金属元素との相互拡散および反応を充分に抑制することができず、負極としての容量が低下してしまう。一方、１５μｍを超える場合は、負極における介在層２の比率が大きくなり、相対的に活物質の粒子１ａの比率が小さくなるため、負極の体積あたりの容量が低下してしまう。介在層２の厚さは、たとえば負極の断面写真を用いて、集電体３と介在層２との界面と、集電体３にもっとも近接している活物質の粒子１ａの表面との最短距離を測定して、介在層２の厚さとすればよい。
The thickness of the intervening layer 2 is preferably 3 μm or more, particularly 3 to 15 μm. When the thickness of the intervening layer 2 is less than 3 μm, the interdiffusion and reaction between Si in the active material particles 1a and the metal element in the conductive material contained in the current collector 3 are sufficiently suppressed. The capacity as a negative electrode is reduced. On the other hand, when the thickness exceeds 15 μm, the ratio of the intervening layer 2 in the negative electrode is increased, and the ratio of the active material particles 1a is relatively decreased. Therefore, the capacity per volume of the negative electrode is decreased. The thickness of the intervening layer 2 is the shortest between the interface between the current collector 3 and the intervening layer 2 and the surface of the active material particle 1a closest to the current collector 3 using, for example, a cross-sectional photograph of the negative electrode. The distance may be measured to obtain the thickness of the intervening layer 2.
なお、介在層２は不可避不純物を１．０質量％以下の割合で含有していても構わない。不可避不純物としては、Ａｌ、Ｓｉ、Ｃｌ等が挙げられる。また、介在層２は、集電体３に含まれる導電性材料中の金属元素と反応しないものであれば、炭素質材料の他に導電助剤（例えば、金や白金等）や活物質を含有していてもよい。介在層２が、集電体３に含まれる導電性材料を構成する金属元素や、活物質の粒子１ａの構成元素を含む場合には、その含有量は３．０質量％以下とするのが好ましい。介在層２中の不可避不純物等の含有量は、負極の断面のうち介在層２の領域を、波長分散型Ｘ線分析（ＷＤＳ）などにより測定すればよい。 The intervening layer 2 may contain inevitable impurities at a ratio of 1.0% by mass or less. Inevitable impurities include Al, Si, Cl and the like. In addition to the carbonaceous material, the intervening layer 2 may be made of a conductive auxiliary (for example, gold or platinum) or an active material as long as it does not react with the metal element in the conductive material contained in the current collector 3. You may contain. When the intervening layer 2 contains a metal element constituting the conductive material contained in the current collector 3 or a constituent element of the active material particles 1a, the content is 3.0% by mass or less. preferable. The content of inevitable impurities and the like in the intervening layer 2 may be measured by wavelength dispersion X-ray analysis (WDS) or the like in the area of the intervening layer 2 in the cross section of the negative electrode.
このように、活物質層１と集電体３との間に炭素質材料からなる介在層２を配置することで、集電体３と活物質層１との間で、それぞれを構成する元素の相互拡散が抑制され、容量の小さい反応生成物の生成を抑制することができる。また、介在層２が、集電体３と充放電により体積変化する活物質層１との緩衝層となり、集電体３の破壊を抑制することができ、容量およびサイクル特性に優れた二次電池用負極となる。 Thus, by disposing the intervening layer 2 made of a carbonaceous material between the active material layer 1 and the current collector 3, the elements constituting each between the current collector 3 and the active material layer 1. Interdiffusion is suppressed, and generation of a reaction product with a small capacity can be suppressed. In addition, the intervening layer 2 becomes a buffer layer between the current collector 3 and the active material layer 1 whose volume is changed by charging / discharging, so that the current collector 3 can be prevented from being destroyed, and the secondary having excellent capacity and cycle characteristics. It becomes a negative electrode for a battery.
なお、活物質層１中に、集電体３に含まれる導電性材料を構成する金属元素が含まれる場合、その含有量は０．０１〜３．０質量％であることが好ましく、さらには０．０１〜１．０質量％であることが好ましい。活物質層１の特に介在層２との界面近傍において、集電体３に含まれる導電性材料を構成する金属元素が拡散している領域が存在している場合、その領域における充放電時の体積変化が抑制され、集電体の破壊を抑制することができる。このような金属元素は、活物質層１中において、介在層２からの距離が大きくなるとともに減少するように分布していることが好ましい。活物質層１全体に含まれる金属元素の含有量は、負極から集電体３および介在層２を除去し、活物質層１のみを取り出して、ＩＣＰ分析等の元素分析により測定すればよい。活物質層１中の金属元素の分布については、負極断面の波長分散型Ｘ線分析（ＷＤＳ）による面分析（マッピング）などの方法で確認すればよい。 In addition, when the metal element which comprises the electroconductive material contained in the electrical power collector 3 is contained in the active material layer 1, it is preferable that the content is 0.01-3.0 mass%, Furthermore, It is preferable that it is 0.01-1.0 mass%. When there is a region where the metal element constituting the conductive material contained in the current collector 3 is diffused, particularly in the vicinity of the interface of the active material layer 1 with the intervening layer 2, charging / discharging in that region is performed. Volume change is suppressed and destruction of the current collector can be suppressed. Such a metal element is preferably distributed in the active material layer 1 so as to decrease as the distance from the intervening layer 2 increases. The content of the metal element contained in the entire active material layer 1 may be measured by removing the current collector 3 and the intervening layer 2 from the negative electrode, taking out only the active material layer 1, and performing elemental analysis such as ICP analysis. The distribution of the metal element in the active material layer 1 may be confirmed by a method such as surface analysis (mapping) by wavelength dispersion X-ray analysis (WDS) of the negative electrode cross section.
さらに、介在層２もしくは活物質層１で覆われていない集電体３の表面、および活物質層１の表面は、炭素質材料で被覆されていることが好ましい。これにより、二次電池を構成した際に、集電体３に含まれる導電性材料や活物質の粒子１ａが、直接電解液と接触することを防ぎ、活物質層１や集電体３の表面における電解液の分解反応の進行や、導電性材料や活物質の構成元素の溶出を抑制することができる。 Furthermore, the surface of the current collector 3 that is not covered with the intervening layer 2 or the active material layer 1 and the surface of the active material layer 1 are preferably covered with a carbonaceous material. As a result, when the secondary battery is configured, the conductive material and active material particles 1a contained in the current collector 3 are prevented from coming into direct contact with the electrolytic solution, and the active material layer 1 and the current collector 3 The progress of the decomposition reaction of the electrolytic solution on the surface and the elution of the constituent elements of the conductive material and the active material can be suppressed.
本発明の二次電池用負極は、たとえば以下のような製法で作製できる。 The negative electrode for a secondary battery of the present invention can be produced, for example, by the following production method.
まず、導電性材料を含む集電体３の表面に、炭素質材料または熱処理により炭化して炭素質材料となる材料を含む介在層前駆体被膜を形成する。導電性材料を含む集電体３としては、導電性フィラーを含むシートや、導電性の金属箔や金属メッシュ等を用いる。 First, an intervening layer precursor film containing a carbonaceous material or a material that is carbonized by heat treatment to become a carbonaceous material is formed on the surface of the current collector 3 containing a conductive material. As the current collector 3 containing a conductive material, a sheet containing a conductive filler, a conductive metal foil, a metal mesh, or the like is used.
炭素質材料としては黒鉛、難黒鉛化性炭素、ガラス状炭素などが挙げられ、これらを混合して用いてもよい。熱処理により炭化して炭素質材料となる材料としては、フェノール樹脂、エポキシ樹脂、ポリエステル樹脂、フラン樹脂、尿素樹脂、メラミン樹脂、アルキッド樹脂、キシレン樹脂等の熱硬化性樹脂、ナフタレン、アセナフチレン、フェナントレ
ン、アントラセン、トリフェニレン、ピレン、ペリレン、ペンタフェン、ペンタセン等の縮合系多環炭化水素化合物またはその誘導体、あるいはその混合物を主成分とするピッチ等の有機材料が挙げられる。なお、熱処理により炭化して炭素質材料となる材料には、さらに上述の炭素質材料を加えることも可能である。また、気孔を形成するために、焼成時に消失して気孔となる樹脂材料等を造孔剤として添加してもよい。
Examples of the carbonaceous material include graphite, non-graphitizable carbon, glassy carbon, and the like. Examples of materials that are carbonized by heat treatment to become a carbonaceous material include thermosetting resins such as phenol resin, epoxy resin, polyester resin, furan resin, urea resin, melamine resin, alkyd resin, xylene resin, naphthalene, acenaphthylene, phenanthrene, Examples thereof include organic materials such as pitch mainly composed of condensed polycyclic hydrocarbon compounds such as anthracene, triphenylene, pyrene, perylene, pentaphen, and pentacene, derivatives thereof, or mixtures thereof. In addition, it is also possible to add the above-mentioned carbonaceous material to the material which carbonizes by heat processing and becomes a carbonaceous material. Further, in order to form pores, a resin material that disappears during firing to become pores may be added as a pore-forming agent.
炭素質材料を用いる場合は、たとえばイソプロピルアルコールなどの溶剤に必要に応じて分散剤や結着材を加えて上述の炭素質材料を分散した介在層形成用塗液を作製して用いればよく、熱処理により炭化して炭素質材料となる材料を用いる場合は、イソプロピルアルコールなどの溶剤に必要に応じて分散剤や結着材を加えて上述の熱処理により炭化して炭素質材料となる材料を分散し、介在層形成用の塗液として用いればよい。このような介在層形成用塗液を用いて、集電体３の表面に周知の方法で塗工し、必要に応じて乾燥することで、介在層前駆体被膜を形成する。 In the case of using a carbonaceous material, for example, a dispersant or a binder may be added to a solvent such as isopropyl alcohol as necessary to prepare and use a coating liquid for forming an intervening layer in which the above-described carbonaceous material is dispersed. When using carbonaceous material that is carbonized by heat treatment, if necessary, add a dispersant or binder to a solvent such as isopropyl alcohol, and disperse carbonaceous material that is carbonized by the above heat treatment. And may be used as a coating liquid for forming an intervening layer. Using such a coating liquid for forming an intervening layer, the surface of the current collector 3 is applied by a well-known method, and dried as necessary to form an intervening layer precursor film.
次に、集電体３の介在層前駆体被膜上に、ＳｉまたはＳｉを含む化合物の原料粉末と、炭素質材料または熱処理により炭化して炭素質材料となる材料と、を含む活物質層前駆体を形成する。ＳｉおよびＳｉを含む化合物の原料粉末は、結晶質、非晶質のいずれでもよく、Ｓｉを含む化合物としては、ＳｉとＣを含む化合物、酸化ケイ素、Ｌｉ、Ｔｉ、Ｌａ、Ｆｅ、Ｖ、Ｃｒ、Ｎｉ、Ｎｂ、Ｍｇ、Ｓｎ、Ｇｅ、Ａｌ、Ａｇ、Ｉｎ、ＧａおよびＳｂからなる金属群から選ばれる少なくとも１種の金属元素とＳｉとの合金などのほか、熱処理によりＳｉに変化しうるシリコン樹脂やＳｉ含有有機化合物などの材料が挙げられる。 Next, on the intervening layer precursor coating of the current collector 3, an active material layer precursor including Si or Si-containing raw material powder and a carbonaceous material or a material carbonized by heat treatment to become a carbonaceous material Form the body. The raw material powder of the compound containing Si and Si may be either crystalline or amorphous. Examples of the compound containing Si include a compound containing Si and C, silicon oxide, Li, Ti, La, Fe, V, and Cr. Ni, Nb, Mg, Sn, Ge, Al, Ag, In, Ga, and an alloy of Si with at least one metal element selected from the metal group, and silicon that can be changed to Si by heat treatment Examples thereof include materials such as resins and Si-containing organic compounds.
活物質層前駆体の形成に用いるＳｉまたはＳｉを含む化合物の原料粉末の平均粒径は、粉砕の容易性、ハンドリング性等から０．０５μｍ以上であることが好ましく、充放電時の体積変化の影響を抑制する点から５μｍ以下であることが好ましい。 The average particle size of the raw material powder of Si or a compound containing Si used for forming the active material layer precursor is preferably 0.05 μm or more from the viewpoint of ease of pulverization, handling properties, etc. It is preferable that it is 5 micrometers or less from the point which suppresses an influence.
炭素質材料または熱処理により炭化して炭素質材料となる材料としては、上述の介在層前駆体被膜の形成に用いたものと同様な材料を用いればよい。また、気孔を形成するために、焼成時に消失して気孔となる樹脂材料等を造孔剤として添加してもよい。 As a carbonaceous material or a material that is carbonized by heat treatment to become a carbonaceous material, a material similar to that used for forming the intervening layer precursor film may be used. Further, in order to form pores, a resin material that disappears during firing to become pores may be added as a pore-forming agent.
ＳｉまたはＳｉを含む化合物の原料粉末と、炭素質材料または熱処理により炭化して炭素質材料となる材料とを、必要に応じて溶媒や分散剤、結着材を加えて活物質層形成用の塗液とし、集電体３の表面に形成した介在層前駆体被膜上に周知の方法で塗工し、必要に応じて乾燥することで、活物質層前駆体を形成する。 The raw material powder of Si or a compound containing Si and a carbonaceous material or a material that is carbonized by heat treatment to become a carbonaceous material are added with a solvent, a dispersant, or a binder as necessary for forming an active material layer. The active material layer precursor is formed by applying the coating liquid on the intermediate layer precursor film formed on the surface of the current collector 3 by a well-known method and drying as necessary.
介在層前駆体被膜および活物質層前駆体を形成した集電体３を、非酸化性雰囲気中で焼成することで、集電体３、介在層２および活物質層１がこの順で積層、一体化した二次電池用負極が得られる。焼成温度は、熱処理により炭化して炭素質材料となる材料を充分炭化させるという点から６００℃以上であることが好ましく、集電体に含まれる導電性材料の融点または分解温度以下とする。例えば、導電性材料として銅を用いる場合は、焼成温度は１０８３℃以下とする。 The current collector 3 on which the intervening layer precursor film and the active material layer precursor are formed is fired in a non-oxidizing atmosphere, so that the current collector 3, the intervening layer 2 and the active material layer 1 are laminated in this order. An integrated negative electrode for a secondary battery is obtained. The firing temperature is preferably 600 ° C. or higher from the viewpoint of sufficiently carbonizing a material that is carbonized by heat treatment to become a carbonaceous material, and is lower than the melting point or decomposition temperature of the conductive material contained in the current collector. For example, when copper is used as the conductive material, the firing temperature is 1083 ° C. or lower.
なお、活物質中のＳｉと、集電体３に含まれる導電性材料中の金属元素との相互拡散および反応は、特に集電体３と活物質層１とを同時焼成して一体化する際に起こり易く、焼成温度が高すぎると、介在層前駆体被膜や介在層２の有無にかかわらず元素が拡散する可能性があるため、焼成温度は特に９００℃以下とすることが好ましい。また、炭素質材料の電子伝導性を充分に発現させるという点から、焼成温度は７００℃以上であることが好ましい。 Note that the mutual diffusion and reaction between Si in the active material and the metal element in the conductive material included in the current collector 3 are integrated by firing the current collector 3 and the active material layer 1 at the same time. If the firing temperature is too high, the element may diffuse regardless of the presence or absence of the intervening layer precursor coating or the intervening layer 2, and the firing temperature is particularly preferably 900 ° C. or lower. Moreover, it is preferable that a calcination temperature is 700 degreeC or more from the point that the electronic conductivity of a carbonaceous material is fully expressed.
本発明の二次電池は、正極と、非水電解質と、上述の二次電池用負極とを備えており、
正極に用いる活物質としては、リチウムコバルト複合酸化物、リチウムマンガン複合酸化物、二酸化マンガン、リチウムニッケル複合酸化物、リチウムニッケルコバルト複合酸化物、リチウムバナジウム複合酸化物、酸化バナジウムなどが挙げられる。このうち、リチウムコバルト複合酸化物は電子伝導性が高く、出力特性に優れた二次電池とすることができる。また、リチウムニッケルマンガン複合酸化物（ＬｉＮｉｘＭｎｙＯ４（ｘ＝０．１〜０．５、ｙ＝１．５〜１．９））は、他の材料に比べ電位が高く、起電力の高い二次電池とすることが出来る。なお、正極は相対密度の高い焼結体として用いることが好ましく、その相対密度は８５％以上、さらには９０％以上であることが好ましい。
The secondary battery of the present invention includes a positive electrode, a non-aqueous electrolyte, and the above-described negative electrode for a secondary battery,
Examples of the active material used for the positive electrode include lithium cobalt composite oxide, lithium manganese composite oxide, manganese dioxide, lithium nickel composite oxide, lithium nickel cobalt composite oxide, lithium vanadium composite oxide, and vanadium oxide. Among these, the lithium cobalt composite oxide has a high electron conductivity and can be a secondary battery excellent in output characteristics. Further, lithium nickel manganese composite oxide (LiNi x Mn y O 4 (x = 0.1 to 0.5, y = 1.5 to 1.9)) has a higher potential than other materials, and an electromotive force. High secondary battery. The positive electrode is preferably used as a sintered body having a high relative density, and the relative density is preferably 85% or more, and more preferably 90% or more.
また、非水電解質としては、有機電解液、高分子固体電解質、無機固体電解質、イオン液体等のいずれも用いることができる。 Further, as the non-aqueous electrolyte, any of an organic electrolytic solution, a polymer solid electrolyte, an inorganic solid electrolyte, an ionic liquid, and the like can be used.
有機電解液を用いる場合は、正極と負極との間にセパレータを配する。有機電解液は、有機溶媒と電解質塩によって構成され、必要に応じて、電極表面への固体電解質層の形成抑制、過充電防止、難燃性の付与等を目的とした添加剤を加えてもよい。 When using an organic electrolyte, a separator is disposed between the positive electrode and the negative electrode. The organic electrolyte is composed of an organic solvent and an electrolyte salt, and if necessary, additives for the purpose of suppressing formation of a solid electrolyte layer on the electrode surface, preventing overcharge, imparting flame retardancy, etc. may be added. Good.
有機溶媒としては、高誘電率を有し、低粘性、低蒸気圧のものが好適に用いられ、このような材料としては、たとえば、エチレンカーボネイト、プロピレンカーボネイト、ブチレンカーボネイト、γ−ブチロラクトン、スルホラン、１，２−ジメトキシエタン、１，３−ジメトキシプロパン、ジメチルエーテル、テトラヒドロフラン、２−メチルテトラヒドロフラン、炭酸ジメチル、炭酸ジエチル、メチルエチルカーボネイト、ジメチルカーボネイト、ジエチルカーボネイトなどから選ばれる１種もしくは２種以上を混合した溶媒が挙げられる。 As the organic solvent, those having a high dielectric constant, low viscosity and low vapor pressure are preferably used. Examples of such materials include ethylene carbonate, propylene carbonate, butylene carbonate, γ-butyrolactone, sulfolane, Mix one or more selected from 1,2-dimethoxyethane, 1,3-dimethoxypropane, dimethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, dimethyl carbonate, diethyl carbonate, etc. Solvent.
電解質塩としては、例えばＬｉＣｌＯ４、ＬｉＢＦ４、ＬｉＰＦ６、ＬｉＣＦ３ＳＯ３、ＬｉＮ(ＣＦ３ＳＯ２)２、ＬｉＮ(Ｃ２Ｆ５ＳＯ２)２などのリチウム塩があげられる。 Examples of the electrolyte salt include lithium salts such as LiClO 4 , LiBF 4 , LiPF 6 , LiCF 3 SO 3 , LiN (CF 3 SO 2 ) 2 , and LiN (C 2 F 5 SO 2 ) 2 .
セパレータには、有機樹脂繊維の不織布や、無機繊維の不織布、セラミックの多孔質材料などを用いることができるが、ポリプロピレンやポリエチレンなどのポリオレフィンを主成分とした有機多孔質膜にセラミック粒子を混合したものや、セラミックフィラーを含む多孔質膜を接着したもの、無機繊維の不織布、有機材料と無機材料の複合多孔質膜、セラミックの多孔質材料を用いることが好ましい。これらは耐熱性が高く、二次電池の熱暴走に対する安全性を高めることができる。 For the separator, a nonwoven fabric of organic resin fibers, a nonwoven fabric of inorganic fibers, a porous ceramic material, etc. can be used. Ceramic particles are mixed in an organic porous film mainly composed of polyolefin such as polypropylene or polyethylene. It is preferable to use a ceramic, a porous membrane containing a ceramic filler, a non-woven fabric of inorganic fibers, a composite porous membrane of an organic material and an inorganic material, or a porous ceramic material. These have high heat resistance and can improve the safety against thermal runaway of the secondary battery.
以下、実施例を用いて本発明を詳細に説明する。 Hereinafter, the present invention will be described in detail using examples.
集電体として、厚み１５μｍの銅箔を準備した。なお、銅箔と介在層とを強固に接着するため、表面の算術平均粗さ（Ｒａ）が１．０μｍの銅箔を用いた。なお、銅箔表面の算術平均粗さ（Ｒａ）は、レーザー顕微鏡を用いて倍率３０００倍で測定した。 A copper foil having a thickness of 15 μm was prepared as a current collector. In order to firmly bond the copper foil and the intervening layer, a copper foil having a surface arithmetic average roughness (Ra) of 1.0 μm was used. The arithmetic average roughness (Ra) of the copper foil surface was measured at a magnification of 3000 times using a laser microscope.
まず、市販のフェノール樹脂を、溶剤であるテトラヒドロフラン（ＴＨＦ）に加えて攪拌し、溶解させたのち、遠心分離により不溶成分を分離することにより、フェノール樹脂溶液を作製した。得られたフェノール樹脂溶液を介在層形成用の塗液として、ドクターブレード法により銅箔の一方の表面上に塗布し、乾燥して介在層前駆体被膜を形成した。 First, a commercially available phenol resin was added to tetrahydrofuran (THF) as a solvent, stirred and dissolved, and then an insoluble component was separated by centrifugation to prepare a phenol resin solution. The obtained phenol resin solution was applied onto one surface of the copper foil by a doctor blade method as a coating solution for forming an intervening layer, and dried to form an intervening layer precursor coating.
次に、作製したフェノール樹脂溶液に、活物質としてＳｉまたはＳｉを含む化合物の原料粉末と、造孔剤として球状アクリル粒子とを加え、さらに攪拌して活物質層形成用の塗液とした。用いた原料粉末の種類を表１に示す。なお、Ｓｉ原料粉末は市販のＳｉ粉末であり、Ｓｉ−Ｔｉ合金の原料粉末はＳｉ粉末およびＴｉ粉末からメカニカルアロイング法
により作製したものである。いずれの原料粉末も、平均粒径が１μｍのものを用いた。
Next, raw material powder of Si or a compound containing Si as an active material and spherical acrylic particles as a pore-forming agent were added to the prepared phenol resin solution, and the mixture was further stirred to obtain a coating solution for forming an active material layer. Table 1 shows the types of raw material powders used. The Si raw material powder is a commercially available Si powder, and the raw material powder of the Si—Ti alloy is produced from the Si powder and the Ti powder by a mechanical alloying method. Any raw material powder having an average particle diameter of 1 μm was used.
銅箔表面に形成した介在層前駆体被膜の上に、作製した活物質層形成用の塗液をドクターブレード法により塗布、乾燥して、活物質層前駆体を形成した。 On the intervening layer precursor film formed on the surface of the copper foil, the prepared coating material for forming an active material layer was applied and dried by a doctor blade method to form an active material layer precursor.
介在層前駆体被膜および活物質層前駆体を形成した銅箔を、窒素雰囲気中にて最高温度９００℃で１０分間焼成することにより、銅箔、介在層および活物質層がこの順で積層、一体化した二次電池用負極を作製した。 By baking the copper foil on which the intervening layer precursor coating and the active material layer precursor are formed at a maximum temperature of 900 ° C. for 10 minutes in a nitrogen atmosphere, the copper foil, the intervening layer, and the active material layer are laminated in this order. An integrated negative electrode for a secondary battery was produced.
作製した二次電池用負極（以下、単に負極ともいう）について、活物質層の構成要素である活物質の粒子、炭素質材料および気孔について、活物質層中における各構成要素の体積比を評価した。各構成要素の体積比は、負極の積層方向に平行な断面を、走査電子顕微鏡（ＳＥＭ）を用いて観察し、波長分散型Ｘ線分析（ＷＤＳ）により活物質の粒子を判別して、画像解析により算出した。結果を表１に示す。介在層の厚さは、同様に走査電子顕微鏡（ＳＥＭ）を用いて負極の積層方向に平行な断面を観察し、集電体と介在層との界面と、集電体にもっとも近接した活物質の粒子の輪郭との最短距離を測定し、これを介在層の厚さとして表１に示した。 For the fabricated negative electrode for secondary battery (hereinafter also simply referred to as negative electrode), the volume ratio of each component in the active material layer was evaluated for the active material particles, carbonaceous material, and pores that are the components of the active material layer. did. The volume ratio of each component is determined by observing a cross section parallel to the lamination direction of the negative electrode using a scanning electron microscope (SEM), discriminating active material particles by wavelength dispersive X-ray analysis (WDS), Calculated by analysis. The results are shown in Table 1. Similarly, the thickness of the intervening layer is observed by using a scanning electron microscope (SEM) to observe a cross section parallel to the stacking direction of the negative electrode. The shortest distance from the particle contour was measured and this is shown in Table 1 as the thickness of the intervening layer.
活物質層中のＣｕの含有量は、負極から銅箔および介在層を機械的に除去して得られた活物質層のＩＣＰ分析を行い、結果を表１に示した。 The content of Cu in the active material layer was determined by performing ICP analysis of the active material layer obtained by mechanically removing the copper foil and the intervening layer from the negative electrode, and the results are shown in Table 1.
作製した二次電池用負極は、直径１５ｍｍφに打ち抜き加工し、対極および参照極としてＬｉ金属を用いてハーフセルを作製して充放電試験を実施した。試験条件を以下に示す。
充電レート ：０．２Ｃ（定電流充電）
放電レート ：１．０Ｃ（定電流放電の後、定電圧放電）
放電終止電圧：０．０１Ｖ
充電終止電圧：２．０Ｖ
測定温度 ：３０℃
サイクル ：放電−充電１回を１サイクルとし、５０サイクル
なお、ここでは負極にＬｉを挿入する場合を放電、負極からＬｉを脱離させる場合を充電とした。また、充放電レート０．２Ｃとは、５時間で電池容量の全てを充電または放電しきる電流値である。
The produced negative electrode for a secondary battery was punched into a diameter of 15 mmφ, a half cell was produced using Li metal as a counter electrode and a reference electrode, and a charge / discharge test was performed. Test conditions are shown below.
Charging rate: 0.2C (constant current charging)
Discharge rate: 1.0 C (constant current discharge followed by constant voltage discharge)
End-of-discharge voltage: 0.01V
End-of-charge voltage: 2.0V
Measurement temperature: 30 ° C
Cycle: One discharge-charge is defined as one cycle and 50 cycles. Here, the case where Li is inserted into the negative electrode is defined as discharge, and the case where Li is desorbed from the negative electrode is defined as charge. The charge / discharge rate of 0.2C is a current value at which the entire battery capacity can be charged or discharged in 5 hours.
充放電試験の結果を表１に示す。なお、充電容量、５０サイクル容量維持率は以下のようにして算出した。
充電容量 ：充電時間×電流値／負極重量
容量維持率 ：サイクル試験後の充電容量／初期の充電容量
The results of the charge / discharge test are shown in Table 1. The charge capacity and 50 cycle capacity maintenance rate were calculated as follows.
Charging capacity: Charging time x current value / negative electrode weight Capacity maintenance ratio: Charging capacity after cycle test / initial charging capacity
表１より、介在層を設けた試料Ｎｏ．１〜９では、介在層を設けなかった試料Ｎｏ．１０に対して大きな容量が得られた。特に、介在層の厚さを３〜１５μｍの範囲とした試料Ｎｏ．１〜３、５〜７では、大きな容量とともに、優れたサイクル特性を有するものとなった。なお、活物質としてＳｉを用いた試料Ｎｏ．１では、容量は大きいもののサイクル特性が不充分であり、サイクル特性の点から、活物質としてはＳｉ−Ｔｉ合金を用いることが好ましい。 From Table 1, Sample No. provided with an intervening layer was used. In Samples Nos. 1 to 9, Sample No. A large capacity for 10 was obtained. In particular, Sample No. with an intervening layer thickness in the range of 3 to 15 μm. 1 to 3 and 5 to 7 had excellent cycle characteristics as well as a large capacity. In addition, sample No. using Si as an active material. In No. 1, the capacity is large, but the cycle characteristics are insufficient. From the viewpoint of the cycle characteristics, it is preferable to use a Si—Ti alloy as the active material.
以上の結果から、活物質の粒子と炭素質材料とを含む焼結体である活物質層と、導電性材料を含む集電体とを備え、活物質がＳｉまたはＳｉを含む化合物であるとともに、活物質層と集電体との間に、炭素質材料からなる介在層を設けることにより、高容量かつサイクル特性にすぐれた二次電池用負極となることがわかる。 From the above results, the active material layer is a sintered body including particles of an active material and a carbonaceous material, and a current collector including a conductive material, and the active material is Si or a compound containing Si. It can be seen that by providing an intervening layer made of a carbonaceous material between the active material layer and the current collector, a negative electrode for a secondary battery having high capacity and excellent cycle characteristics is obtained.
１ ：活物質層
２ ：介在層
３ ：集電体
１ａ ：活物質の粒子
１ｂ、２ｂ：炭素質材料
１ｃ、２ｃ：気孔
1: active material layer 2: intervening layer 3: current collector 1a: particles of active material 1b, 2b: carbonaceous material 1c, 2c: pores
Claims (7)
前記活物質がＳｉまたはＳｉを含む化合物であるとともに、
前記活物質層と前記集電体との間に、炭素質材料からなる介在層を設けたことを特徴とする二次電池用負極。 An active material layer that is a sintered body including particles of an active material and a carbonaceous material, and a current collector including a conductive material,
The active material is Si or a compound containing Si,
A negative electrode for a secondary battery, wherein an intervening layer made of a carbonaceous material is provided between the active material layer and the current collector.
前記介在層前駆体被膜上に、ＳｉまたはＳｉを含む化合物の原料粉末と、炭素質材料または熱処理により炭化して炭素質材料となる材料と、を含む活物質層前駆体を形成する工程と、
前記介在層前駆体被膜および前記活物質層前駆体を形成した前記集電体を、非酸化性雰囲気中で焼成する工程と、を有することを特徴とする二次電池用負極の製法。 Forming an intervening layer precursor coating containing a carbonaceous material or a material that is carbonized by heat treatment to become a carbonaceous material on the surface of the current collector containing the conductive material;
Forming an active material layer precursor containing, on the intervening layer precursor coating, a raw material powder of Si or a compound containing Si, and a carbonaceous material or a material carbonized by heat treatment to become a carbonaceous material;
And baking the current collector on which the intervening layer precursor coating and the active material layer precursor are formed in a non-oxidizing atmosphere, and a method for producing a negative electrode for a secondary battery.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2011283679A JP5908714B2 (en) | 2011-12-26 | 2011-12-26 | Negative electrode for secondary battery, method for producing the same, and secondary battery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2011283679A JP5908714B2 (en) | 2011-12-26 | 2011-12-26 | Negative electrode for secondary battery, method for producing the same, and secondary battery |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2013134863A true JP2013134863A (en) | 2013-07-08 |
| JP5908714B2 JP5908714B2 (en) | 2016-04-26 |
Family
ID=48911429
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2011283679A Expired - Fee Related JP5908714B2 (en) | 2011-12-26 | 2011-12-26 | Negative electrode for secondary battery, method for producing the same, and secondary battery |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP5908714B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2015053221A (en) * | 2013-09-09 | 2015-03-19 | 国立大学法人岩手大学 | Negative electrode for lithium secondary battery |
| KR20180109764A (en) * | 2017-03-28 | 2018-10-08 | 에네베이트 코포레이션 | Methods of forming carbon-silicon composite material on a current collector |
| TWI695536B (en) * | 2018-02-23 | 2020-06-01 | 國立研究開發法人產業技術總合研究所 | Laminate body and manufacturing method thereof |
| US20210376330A1 (en) * | 2017-03-28 | 2021-12-02 | Enevate Corporation | Reaction barrier between electrode active material and current collector |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004288520A (en) * | 2003-03-24 | 2004-10-14 | Sanyo Electric Co Ltd | Negative electrode for lithium secondary battery and lithium secondary battery |
| JP2006269331A (en) * | 2005-03-25 | 2006-10-05 | Sony Corp | Cathode, battery, and manufacturing method of them |
-
2011
- 2011-12-26 JP JP2011283679A patent/JP5908714B2/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004288520A (en) * | 2003-03-24 | 2004-10-14 | Sanyo Electric Co Ltd | Negative electrode for lithium secondary battery and lithium secondary battery |
| JP2006269331A (en) * | 2005-03-25 | 2006-10-05 | Sony Corp | Cathode, battery, and manufacturing method of them |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2015053221A (en) * | 2013-09-09 | 2015-03-19 | 国立大学法人岩手大学 | Negative electrode for lithium secondary battery |
| KR20180109764A (en) * | 2017-03-28 | 2018-10-08 | 에네베이트 코포레이션 | Methods of forming carbon-silicon composite material on a current collector |
| CN108666521A (en) * | 2017-03-28 | 2018-10-16 | 新强能电池公司 | The method that carbon-silicon composite is formed on current-collector |
| JP2018166101A (en) * | 2017-03-28 | 2018-10-25 | エネヴェート・コーポレーション | Method of forming carbon-silicon composite material on current collector |
| US20210376330A1 (en) * | 2017-03-28 | 2021-12-02 | Enevate Corporation | Reaction barrier between electrode active material and current collector |
| KR102551495B1 (en) * | 2017-03-28 | 2023-07-04 | 에네베이트 코포레이션 | Methods of forming carbon-silicon composite material on a current collector |
| CN108666521B (en) * | 2017-03-28 | 2023-08-25 | 新强能电池公司 | Method for forming carbon-silicon composite material on current collector |
| TWI695536B (en) * | 2018-02-23 | 2020-06-01 | 國立研究開發法人產業技術總合研究所 | Laminate body and manufacturing method thereof |
| US11916227B2 (en) | 2018-02-23 | 2024-02-27 | National Institute Of Advanced Industrial Science And Technology | Multilayer body and method for producing same |
Also Published As
| Publication number | Publication date |
|---|---|
| JP5908714B2 (en) | 2016-04-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9577246B2 (en) | Negative electrode active material, negative electrode for nonaqueous electrolyte secondary battery, and nonaqueous electrolyte secondary battery | |
| JP4974597B2 (en) | Negative electrode and negative electrode active material for lithium ion secondary battery | |
| US9865873B2 (en) | Positive electrode mixture and all-solid-state lithium sulfur cell | |
| WO2015098551A1 (en) | Solid-state lithium battery, solid-state lithium battery module, and method for producing solid-state lithium battery | |
| WO2012014998A1 (en) | Lithium secondary battery | |
| JP6194794B2 (en) | Lithium secondary battery | |
| JP5448555B2 (en) | Negative electrode for lithium ion secondary battery, lithium ion secondary battery using the same, slurry for preparing negative electrode for lithium ion secondary battery, and method for producing negative electrode for lithium ion secondary battery | |
| JP2013510405A (en) | High capacity anode materials for lithium ion batteries | |
| JP6704295B2 (en) | All-solid-state lithium secondary battery and manufacturing method thereof | |
| KR101495451B1 (en) | Powder for lithium ion secondary battery negative electrode material, lithium ion secondary battery negative electrode and capacitor negative electrode, and lithium ion secondary battery and capacitor | |
| JP2011233349A (en) | Nonaqueous secondary battery | |
| JP6208443B2 (en) | Secondary battery negative electrode and secondary battery using the same | |
| JP2012181975A (en) | Nonaqueous secondary battery | |
| CN110495026B (en) | Negative electrode material and nonaqueous electrolyte secondary battery | |
| WO2023162716A1 (en) | Negative electrode active material for nonaqueous electrolyte secondary batteries, and nonaqueous electrolyte secondary battery | |
| WO2020196610A1 (en) | Composite particles and negative electrode material for lithium ion secondary batteries | |
| JP5908714B2 (en) | Negative electrode for secondary battery, method for producing the same, and secondary battery | |
| US20240021806A1 (en) | Negative electrode material for non-aqueous electrolyte secondary battery, and non-aqueous electrolyte secondary battery | |
| JP2017050204A (en) | Positive electrode material for nonaqueous electrolyte secondary batteries, method for manufacturing the same and nonaqueous electrolyte secondary battery | |
| JP6117630B2 (en) | Negative electrode material for sodium secondary battery and sodium secondary battery using the same | |
| WO2020213628A1 (en) | Composite carbon particles, method for manufacturing same and use thereof | |
| JP2015115233A (en) | Negative electrode for magnesium ion secondary battery and magnesium ion secondary battery | |
| EP4254550A1 (en) | Negative electrode active material for nonaqueous electrolyte secondary batteries, and nonaqueous electrolyte secondary battery | |
| JP2013247022A (en) | Electrode material, method for producing the same, and secondary battery | |
| JP5440695B2 (en) | Electrode body and secondary battery using the same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20140715 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20150224 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20150225 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20150406 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20150728 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20150903 |
|
| 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: 20160223 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20160324 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 5908714 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| LAPS | Cancellation because of no payment of annual fees |