JP4069465B2 - Carbonaceous negative electrode material for lithium secondary battery and method for producing the same - Google Patents
Carbonaceous negative electrode material for lithium secondary battery and method for producing the same Download PDFInfo
- Publication number
- JP4069465B2 JP4069465B2 JP32241499A JP32241499A JP4069465B2 JP 4069465 B2 JP4069465 B2 JP 4069465B2 JP 32241499 A JP32241499 A JP 32241499A JP 32241499 A JP32241499 A JP 32241499A JP 4069465 B2 JP4069465 B2 JP 4069465B2
- Authority
- JP
- Japan
- Prior art keywords
- lithium
- metal
- negative electrode
- secondary battery
- lithium secondary
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Description
【０００１】
【発明の属する技術分野】
本発明は、炭素質材料およびその製造方法、リチウム二次電池に用いる炭素質負極材及び負極並びにリチウム二次電池に関する。
【０００２】
【従来の技術】
電子機器の小型化、薄型化、軽量化が進む中で、電子機器の電源用の電池として、また電子機器のバックアップ用電池として、高エネルギー密度で充電でき、高効率で放電できるリチウム二次電池が注目を集めている。また、リチウムは、環境に与える影響が少なく、安全性が高いことから、リチウム二次電池は、電気自動車の動力源として、さらに分散型の電力貯蔵用電池としての開発も行われている。
【０００３】
従来の典型的なリチウム二次電池は、負極活物質として炭素材を用い、リチウムをイオン状態で炭素材中に挿入(インターカレーション)および脱離(デインターカレーション)させることにより充放電を繰り返している。しかしながら、炭素材に対するリチウムイオンの挿入量を高めることは困難であり、二次電池としての充放電容量を高めることができないという問題がある。たとえば、黒鉛を炭素質材料として用いると、リチウム金属はCLi6の組成となり、この物質の理論充放電容量は、372Ah/kgである。これは、リチウム金属の理論充放電容量3800Ah/kg（リチウムベース）の1/10以下と低い。充放電容量を改善するために、非晶部の割合の多い炭素材料を用いる場合には、400Ah/kg以上の充放電容量が可能であるとされている。しかしながら、このような炭素材料は、導電性が低いために、過電圧が大きく、初期充放電効率が80%前後と低い値を示す。
今日のように種々の炭素材料が負極に使用される以前には、リチウム金属およびリチウム合金の研究が精力的に行われていた。リチウム金属を負極材料として使用する場合には、充放電時にデンドライトが生成するという問題があり、現状のままでは使用することができない。また、リチウム合金については、充放電に伴うリチウムの出入りにより、合金の結晶構造が大きく変化するので、膨張・収縮に伴う体積変化に起因して、充放電サイクルが100回程度で電極性能が劣化するという問題がある。
【０００４】
【発明が解決しようとする課題】
本発明は、かかる事情を鑑みてなされたものであり、過電圧が低く、放電容量が大きく、サイクル劣化の少ないリチウム二次電池負極用材料、その製造方法、およびこの負極材料を用いたリチウム二次電池を提供することを主な目的とする。
【０００５】
【課題を解決するための手段】
本発明者は、前記のような課題を解決するために鋭意研究を重ねた結果、活性炭粒子の細孔中に、(a)リチウムと合金を形成することができる金属の少なくとも１種、(b)リチウムと合金を形成できる金属を含む２種以上の元素からなる合金の少なくとも１種、および(c)リチウムと合金を形成することができる金属の酸化物、窒化物およびその他の化合物の少なくとも１種から選ばれた金属材料を含有する炭素質材料が、高い導電性および放電容量を有すること、また、リチウム合金形成時に生じる結晶構造の変化による体積変化を活性炭の細孔が吸収するため、サイクル特性が向上することことを見出し、本発明を完成するに至った。
すなわち、本発明は、下記のリチウム二次電池用炭素質負極材、その製造方法、リチウム二次電池負極およびリチウム二次電池を提供するものである。
１．活性炭粒子の細孔中に、下記金属成分(a)〜(c)の少なくとも１種を含有することを特徴とするリチウム二次電池用炭素質負極材；(a)リチウムと合金を形成することができる金属の少なくとも１種、(b)リチウムと合金を形成できる金属を含む２種以上の元素からなる合金の少なくとも１種、および(c)リチウムと合金を形成することができる金属の酸化物、窒化物およびその他の化合物の少なくとも１種。
２．活性炭粒子の平均粒径が、1〜100μmである上記項１に記載のリチウム二次電池用炭素質負極材。
３．活性炭粒子の比表面積が、50m2/g〜5000m2/gである上記項１に記載のリチウム二次電池用炭素質負極材。
４．リチウムと合金を形成することができる金属が、Sn、Ca、Sr、Ba、Ir、Ag、Cd、Hg、B、Al、Ga、In、Ti、Si、Pb、Sb、BiおよびTeから選択される金属である上記項１に記載のリチウム二次電池用炭素質負極材。
５．金属成分(b)リチウムと合金を形成できる金属を含む２種以上の元素からなる合金の少なくとも１種、および(c)リチウムと合金を形成することができる金属の酸化物、窒化物およびその他の化合物の少なくとも１種が、遷移金属および典型金属の少なくとも１種を含む上記項１記載のリチウム二次電池用炭素質負極材。
６．活性炭粒子重量に対する金属成分(a)〜(c)の少なくとも１種の比率が、1〜80重量％である上記項１に記載のリチウム二次電池用炭素質負極材。
７．（Ｉ）溶媒中で、活性炭粒子に下記金属成分(a)〜(c)の少なくとも１種を含浸させ、担持させることにより、活性炭-金属複合体を得る工程、および（II）得られた活性炭-金属複合体を加熱処理する工程を含むことを特徴とするリチウム二次電池用炭素質材料の製造方法；(a)リチウムと合金を形成することができる金属の少なくとも１種、(b)リチウムと合金を形成できる金属を含む２種以上の元素からなる合金の少なくとも１種、および(c)リチウムと合金を形成することができる金属の酸化物、窒化物およびその他の化合物の少なくとも１種。
８．活性炭の細孔中に、金属成分(a)〜(c)の少なくとも１種を担持した後、2800℃以下の不活性雰囲気中、窒素雰囲気中あるいは酸化性雰囲気中で熱処理する上記項７記載のリチウム二次電池用炭素質負極材の製造方法。
９．非水電解質と、正極と、リチウムを吸蔵/放出する負極を用いたリチウム二次電池において、負極材料として上記項１に記載の炭素質負極材料を用いることを特徴とするリチウム二次電池。
１０．上記項１に記載の金属質含有炭素質負極材料に対し、導電材として炭素質材料を1〜30重量％添加して構成した負極を用いる上記項９に記載のリチウム二次電池。
【０００６】
【発明の実施の形態】
負極材料
本発明では、活性炭の細孔中に、(a)リチウムと合金を形成することができる金属の少なくとも１種、(b)リチウムと合金を形成できる金属を含む２種以上の元素からなる合金の少なくとも１種、および(c)リチウムと合金を形成することができる金属の酸化物、窒化物およびその他の化合物の少なくとも１種から選ばれた金属成分の少なくとも１種を含有する炭素質材料をリチウム二次電池用炭素質負極材として使用する。
活性炭粒子としては、平均粒径が1〜100μmであり、比表面積が50〜5000m2/gであるものを用いることができる。その原料、製造方法などは特に限定されるものではないが、例えば、常法に従って、木材、ヤシ殻、石炭、砂糖炭、ピッチなどを原料として調製した炭素質材料などを賦活処理することにより得ることができる。賦活処理の条件なども、炭素質材料の比表面積を大きくすることができる限り、特に制限はなく、炭素質材料を水蒸気、二酸化炭素、酸素あるいはこれらの混合物あるいはこれらのガスを窒素などの不活性ガスで希釈したガスなど雰囲気中800〜1200℃で保持する方法；炭素質材料を水酸化アルカリと混合して活性化温度に加熱処理する方法などが例示される。また、活性炭素粒子は、賦活前には粒子状である必要はなく、例えば石油あるいは石炭系ピッチなど紡糸することにより繊維状に調製した炭素質材料を賦活処理した後、粉砕して用いることもできる。
なお、本明細書において、活性炭粒子の平均粒径とは、乾式レーザー回折測定法によりより得られた体積粒度分布における中心粒径を意味する。また、比表面積は、BET法により測定した数値を示す。
【０００７】
リチウムと合金を形成する金属としては、例えば、IIA族元素(例えばCa、Sr、Ba)、VIIIB族元素(例えばIr)、ＩB族元素(例えばAg)、IIB族元素(例えばCd、Hg)、IIIB族元素(例えばB、Al、Ga、In、Ti)、IVB族元素(Sn)、ＶB族元素(例えばSb、Bi)、VIB族元素（例えばTe）などが挙げられる。これらの元素は単独で、あるいは２種以上を使用することができる。また、これらの元素は、化合物の形態であっても良い。具体的には、リチウムと合金を形成する金属の炭化物、窒化物、有機酸塩（例えば酢酸塩）、無機酸塩（例えば塩化物、炭酸塩、硝酸塩）などとして使用することができる。本明細書中では、上記の元素および化合物を「金属成分」と表記する場合がある。なお、本明細書中の元素の「族」表示は、“岩波理化学辞典；第５版”中の「元素の周期表(短周期型)」による。
活性炭素粒子に対する金属成分の使用量を調節することにより、活性炭の細孔中のリチウムと合金を形成する元素の含有量を制御することができる。最終的な歩留まりを考慮して、活性炭重量に対し、リチウムと合金を形成する金属成分の比率を1〜80重量％となるように調節することができる。通常の調製方法としては、適当な比表面積を有する活性炭と、リチウムと合金を形成できる金属単独、あるいは該金属を含む２種以上の元素からなる合金、あるいはこれら金属の化合物とを適当な溶媒中で含浸することにより、これらの金属成分を担持した炭素材を調製する。例えば、リチウムと合金を形成する金属としてSnを選んだ場合、所定量の活性炭とSn(CH2CO2)2をエタノール中で含浸・担持させることができる。
上記の様にして、所定重量比に調製された活性炭-担持金属複合材料は、不活性雰囲気中、窒素雰囲気中あるいは酸化性雰囲気中で熱処理することにより、活性炭の細孔中にリチウムと合金を形成できる金属あるいはこの金属を含む２種以上の元素からなる合金あるいは金属の化合物(酸化物、窒化物など)を形成することができる。熱処理温度は、例えば、800〜1500℃程度、より好ましくは1000〜1300℃程度に加熱することにより、実施することができる。
同じ比表面積の活性炭粒子を用いる場合にも、活性炭と金属成分との重量比率を変えることにより、活性炭粒子の細孔中に含有される金属成分の粒径をも制御することができる。例えば、比表面積700m2/gの活性炭を用いて、Sn(CH2CO2)2をエタノール溶媒中で含浸・担持した後、不活性雰囲気中1000℃で処理することにより、活性炭の細孔中にSn金属を担持させ場合、Snの結晶子サイズは、Sn量14wt%の時30nm、33wt%の時40nm、45wt%の時50nmのように、制御することができる。
リチウム二次電池用負極
本発明の炭素質負極材は、常法により、リチウム二次電池用負極の構成材料として使用することができる。本発明の炭素質負極用材を、常法により、必要に応じて端子と組み合わせて成形することにより、任意な形状のリチウム二次電池用負極とすることができる。
【０００８】
本発明の炭素質負極材は、ポリフッ化ビニリデン、ポリテトラフルオロエチレンなどの樹脂の分散液と混合することにより、ペースト状として用いることもできる。樹脂の混合量については、特に限定はないが、通常、炭素質負極材100重量部に対して、例えば、下限は3重量部以上、好ましくは5重量部以上、上限は30重量部以下、好ましくは20重量部以下とすることができる。分散液の溶媒としては、例えば、N-メチルピロリドンなどの有機溶媒を用いることができる。また、負極材料に対し、導電材として炭素質材料を1〜30重量％添加して構成した負極を用いることにより、電極としての導電性を向上させることができ、更に放電容量とサイクル特性を向上させることができる。この様な添加炭素質材料としては、アセチレンブラック、サーマルブラック、ファーネスブラックなどのカーボンブラックが例示される。これらは、単独で使用しても良く、あるいは２種以上を併用しても良い。
リチウム二次電池
本発明のリチウム二次電池用負極を構成要素として用いることにより、充放電容量が大きく、初期効率が高いリチウム二次電池を作製することができる。具体的には、上記の方法で得られる本発明の負極を構成要素とし、正極、電解質（電解液）などと組み合わせて、常法により、リチウム二次電池を作製することができる。
【０００９】
正極括物質としては、例えば、LiCoO2、LiNiO2、LiMn2O4などを使用することができる。
【００１０】
電解液として、有機溶媒に電解質を溶解させた電解液を用いることにより、非水系リチウム二次電池を作製することができる。電解質としては、例えば、LiPF6、LiClO4、LiBF4、LiAsF6、LiSbF6、LiAlO4、LiAlCl4、LiCl、LiIなどの溶媒和しにくいアニオンを生成する塩を用いることができる。
【００１１】
有機溶媒としては、例えば、プロピレンカーボネート、エチレンカーボネート、ジエチルカーボネート、γ一ブチルラクトン、テトラヒドロフラン、2-メチルテトラヒドロフラン、ジオキソラン、4-メチルジオキソラン、スルホラン、1,2-ジメトキシエタン、ジメチルスルホキシド、アセトニトリル、N,N-ジメチルホルムアミド、ジエチレングリコール、ジメチルエーテルなどの非プロトン性溶媒を単独で又は2種類以上の混合溶媒として用いることができる。
リチウム二次電池を製造する場合には、上記の負極材料、正極材料、および電解液とともに、通常使用される多孔質ポリプロピレン製不繊布をはじめとするポリオレフィン系の多孔質膜のセパレータ、集電体、ガスケット、封口板、ケースなどの電池構成要素を使用して、常法に従って、円筒型、角型、ボタン型などの任意の形態のリチウム二次電池を作製することができる。
【００１２】
【発明の効果】
本発明によれば、リチウムと合金を形成する金属粒子が、活性炭粒子の細孔中に均一に分散した炭素質材料を製造することができる。この様な炭素質材料は、リチウム二次電池用炭素質負極材として優れた特性を有する。従って、本発明によれば、充放電容量が大きく且つ初期効率が高いリチウム二次電池を提供することができる。
【００１３】
【実施例】
以下、実施例により本発明をより具体的に説明する。
実施例１
＊炭素質材料の製造
ピッチ系活性炭素繊維（比表面積700m2/g）1.1gとSnSO41gとを0.01N希硫酸500mL中で２時間撹拌し、溶媒を蒸発させることにより、含浸・担持処理を行った。
【００１４】
次いで、含浸・担持処理を行った試料を乾燥した後、通常の熱処理炉において、アルゴン気流中、昇温速度10℃/minで1000℃まで昇温し、その温度で1時間保持することにより、処理を行った。焼成後の重量は、1.2gであり、活性炭素繊維の収率を考慮して、活性炭に担持されたSnの割合は、33重量％と求められた。
【００１５】
電極は、熱処理後の試料にバインダー(PVDF)のNMP溶液を加え、試料重量を基準として、アセチレンブラック15wt%を添加した後、銅箔上に塗布することにより作成した。
【００１６】
充放電試験は、作成した電極と対極に金属リチウム、電解液に LiPF6/EC:DMC=1:1の1M溶液を使用し、低電流法（電流密度0.5mA/cm2）、電圧範囲0〜1.5Vで二極式密閉セルを用いて行った。
【００１７】
結果を表１および図１に示す。表１は、実施例２および比較例１〜２で得られた結果を併せて示す、図１は、実施例２および比較例１で得られた結果を併せて示す。
実施例２
実施例１と同様にして炭素質材料を得た後、アセチレンブラックを添加しない以外は実施例１と同様にして電極塗膜調製を行い、電極評価試験を実施した。
比較例１
粉末のSnとピッチ系活性炭素繊維（比表面積700m2/g）を乳鉢で混合した以外は実施例１と同様にして炭素質材料を得た後、アセチレンブラックを添加しない以外は実施例１と同様にして電極塗膜調製を行い、電極評価試験を実施した。
比較例２
金属を担持しないピッチ系活性炭素繊維（比表面積700m2/g）を使用する以外は実施例１と同様にして熱処理および電極塗膜調製を行い、電極評価試験を実施した。
【００１８】
【表１】
表１および図１に示す結果から、本発明による負極材料は、放電容量が大きく、サイクル劣化が少ないことが明らかである。
【図面の簡単な説明】
【図１】実施例および比較例で得られた負極材料のサイクル特性を示すグラフである。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a carbonaceous material and a method for producing the same, a carbonaceous negative electrode material and a negative electrode used for a lithium secondary battery, and a lithium secondary battery.
[0002]
[Prior art]
Lithium secondary batteries that can be charged with high energy density and discharged with high energy density as power source batteries for electronic devices and as backup batteries for electronic devices as electronic devices become smaller, thinner, and lighter Has attracted attention. In addition, since lithium has little impact on the environment and high safety, lithium secondary batteries have been developed as power sources for electric vehicles and further as distributed power storage batteries.
[0003]
A conventional typical lithium secondary battery uses a carbon material as a negative electrode active material, and is charged and discharged by inserting (intercalating) and desorbing (deintercalating) lithium into the carbon material in an ionic state. It is repeating. However, it is difficult to increase the amount of lithium ions inserted into the carbon material, and there is a problem that the charge / discharge capacity of the secondary battery cannot be increased. For example, when graphite is used as the carbonaceous material, the lithium metal has a composition of CLi 6 and the theoretical charge / discharge capacity of this material is 372 Ah / kg. This is as low as 1/10 or less of the lithium metal theoretical charge / discharge capacity of 3800 Ah / kg (lithium base). In order to improve the charge / discharge capacity, when using a carbon material with a high proportion of amorphous parts, it is said that a charge / discharge capacity of 400 Ah / kg or more is possible. However, since such a carbon material has low conductivity, the overvoltage is large and the initial charge / discharge efficiency is as low as about 80%.
Prior to the use of various carbon materials for the negative electrode, as in today, lithium metal and lithium alloys have been intensively studied. When lithium metal is used as a negative electrode material, there is a problem that dendrites are generated during charging and discharging, and cannot be used as they are. In addition, for lithium alloys, the crystal structure of the alloy changes greatly due to the entry and exit of lithium accompanying charge / discharge, so the electrode performance deteriorates after about 100 charge / discharge cycles due to volume changes associated with expansion / contraction. There is a problem of doing.
[0004]
[Problems to be solved by the invention]
The present invention has been made in view of such circumstances, and a lithium secondary battery negative electrode material having a low overvoltage, a large discharge capacity, and a small cycle deterioration, a method for producing the same, and a lithium secondary using the negative electrode material The main purpose is to provide a battery.
[0005]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the present inventor has found that (a) at least one metal capable of forming an alloy with lithium in the pores of the activated carbon particles, (b At least one alloy of two or more elements including a metal capable of forming an alloy with lithium, and (c) at least one of oxides, nitrides and other compounds of metals capable of forming an alloy with lithium. The carbonaceous material containing the metal material selected from the seeds has high conductivity and discharge capacity, and the activated carbon pores absorb the volume change due to the change in crystal structure that occurs during the formation of the lithium alloy. The inventors have found that the characteristics are improved and have completed the present invention.
That is, this invention provides the following carbonaceous negative electrode material for lithium secondary batteries, its manufacturing method, a lithium secondary battery negative electrode, and a lithium secondary battery.
1. A carbonaceous negative electrode material for a lithium secondary battery containing at least one of the following metal components (a) to (c) in the pores of the activated carbon particles; (a) forming an alloy with lithium At least one metal that can form an alloy, (b) at least one alloy composed of two or more elements including a metal that can form an alloy with lithium, and (c) an oxide of a metal that can form an alloy with lithium , At least one of nitrides and other compounds.
2. Item 2. The carbonaceous negative electrode material for a lithium secondary battery according to
3. The specific surface area of the activated carbon particles, 50m 2 / g~5000m 2 / g and a lithium secondary battery carbonaceous negative electrode material according to 1.
4). Metals that can form alloys with lithium are selected from Sn, Ca, Sr, Ba, Ir, Ag, Cd, Hg, B, Al, Ga, In, Ti, Si, Pb, Sb, Bi and Te Item 2. The carbonaceous negative electrode material for a lithium secondary battery according to
5. Metal component (b) at least one alloy composed of two or more elements including a metal capable of forming an alloy with lithium, and (c) an oxide, nitride and other metals capable of forming an alloy with lithium Item 2. The carbonaceous negative electrode material for a lithium secondary battery according to
6). The carbonaceous negative electrode material for a lithium secondary battery according to
7). (I) a step of obtaining an activated carbon-metal composite by impregnating and supporting at least one of the following metal components (a) to (c) in activated carbon particles in a solvent; and (II) the obtained activated carbon A method for producing a carbonaceous material for a lithium secondary battery, comprising a step of heat-treating a metal composite; (a) at least one metal capable of forming an alloy with lithium; (b) lithium And (c) at least one of metal oxides, nitrides and other compounds capable of forming an alloy with lithium.
8). Item 8. The above item 7, wherein at least one of the metal components (a) to (c) is supported in the pores of the activated carbon and then heat-treated in an inert atmosphere at 2800 ° C. or lower, in a nitrogen atmosphere or in an oxidizing atmosphere. A method for producing a carbonaceous negative electrode material for a lithium secondary battery.
9. A lithium secondary battery using a nonaqueous electrolyte, a positive electrode, and a negative electrode that occludes / releases lithium, wherein the carbonaceous negative electrode material described in the
10.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Negative electrode material In the present invention, in the pores of activated carbon, (a) at least one metal capable of forming an alloy with lithium and (b) two or more metals including a metal capable of forming an alloy with lithium. And at least one metal alloy selected from at least one metal oxide, nitride and other compound capable of forming an alloy with lithium. The carbonaceous material to be used is used as a carbonaceous negative electrode material for a lithium secondary battery.
As the activated carbon particles, those having an average particle diameter of 1 to 100 μm and a specific surface area of 50 to 5000 m 2 / g can be used. Although the raw material, a manufacturing method, etc. are not specifically limited, For example, according to a conventional method, it obtains by activating treatment of the carbonaceous material etc. which prepared wood, coconut shell, coal, sugar charcoal, pitch, etc. as a raw material be able to. The conditions for the activation treatment are not particularly limited as long as the specific surface area of the carbonaceous material can be increased, and the carbonaceous material is inert such as water vapor, carbon dioxide, oxygen or a mixture thereof, or these gases are inert such as nitrogen. Examples thereof include a method of holding at 800 to 1200 ° C. in an atmosphere such as a gas diluted with a gas; a method of mixing a carbonaceous material with an alkali hydroxide and performing a heat treatment at an activation temperature. Further, the activated carbon particles need not be in the form of particles before activation. For example, the activated carbon particles may be used after being pulverized after activating the carbonaceous material prepared in a fibrous form by spinning such as petroleum or coal-based pitch. it can.
In the present specification, the average particle size of the activated carbon particles means the center particle size in the volume particle size distribution obtained by the dry laser diffraction measurement method. The specific surface area is a numerical value measured by the BET method.
[0007]
Examples of the metal that forms an alloy with lithium include a group IIA element (for example, Ca, Sr, Ba), a group VIIIB element (for example, Ir), a group IB element (for example, Ag), a group IIB element (for example, Cd, Hg), Examples include IIIB group elements (for example, B, Al, Ga, In, Ti), IVB group elements (Sn), VB group elements (for example, Sb, Bi), and VIB group elements (for example, Te). These elements can be used alone or in combination of two or more. These elements may be in the form of compounds. Specifically, it can be used as a carbide, nitride, organic acid salt (for example, acetate), inorganic acid salt (for example, chloride, carbonate, nitrate) of a metal that forms an alloy with lithium. In the present specification, the above elements and compounds are sometimes referred to as “metal components”. In addition, the “group” designation of elements in this specification is based on “periodic table of elements (short-period type)” in “Iwanami Dictionary of Chemical Sciences; Fifth Edition”.
By adjusting the amount of the metal component used with respect to the activated carbon particles, the content of elements forming an alloy with lithium in the pores of the activated carbon can be controlled. Considering the final yield, the ratio of the metal component forming an alloy with lithium can be adjusted to 1 to 80% by weight with respect to the weight of the activated carbon. As an ordinary preparation method, activated carbon having an appropriate specific surface area, a metal capable of forming an alloy with lithium alone, an alloy composed of two or more elements containing the metal, or a compound of these metals in an appropriate solvent. The carbon material carrying these metal components is prepared by impregnating with. For example, when Sn is selected as a metal that forms an alloy with lithium, a predetermined amount of activated carbon and Sn (CH 2 CO 2 ) 2 can be impregnated and supported in ethanol.
The activated carbon-supported metal composite material prepared at a predetermined weight ratio as described above is subjected to heat treatment in an inert atmosphere, a nitrogen atmosphere or an oxidizing atmosphere, whereby lithium and an alloy are formed in the pores of the activated carbon. A metal that can be formed, an alloy composed of two or more elements containing the metal, or a metal compound (oxide, nitride, etc.) can be formed. The heat treatment temperature can be carried out, for example, by heating to about 800 to 1500 ° C, more preferably about 1000 to 1300 ° C.
Even when activated carbon particles having the same specific surface area are used, the particle size of the metal component contained in the pores of the activated carbon particles can be controlled by changing the weight ratio between the activated carbon and the metal component. For example, after impregnating and supporting Sn (CH 2 CO 2 ) 2 in an ethanol solvent using activated carbon having a specific surface area of 700 m 2 / g, treatment in an inert atmosphere at 1000 ° C. In the case where Sn metal is supported on Sn, the crystallite size of Sn can be controlled such as 30 nm when the Sn amount is 14 wt%, 40 nm when 33 wt%, and 50 nm when 45 wt%.
Negative electrode for lithium secondary battery The carbonaceous negative electrode material of the present invention can be used as a constituent material of a negative electrode for a lithium secondary battery by a conventional method. The material for a carbonaceous negative electrode of the present invention can be formed into a negative electrode for a lithium secondary battery having an arbitrary shape by molding in combination with a terminal as necessary according to a conventional method.
[0008]
The carbonaceous negative electrode material of the present invention can also be used as a paste by mixing with a dispersion of a resin such as polyvinylidene fluoride or polytetrafluoroethylene. The mixing amount of the resin is not particularly limited, and is usually 3 parts by weight or more, preferably 5 parts by weight or more, and preferably 30 parts by weight or less, preferably the lower limit with respect to 100 parts by weight of the carbonaceous negative electrode material. Can be 20 parts by weight or less. As a solvent for the dispersion, for example, an organic solvent such as N-methylpyrrolidone can be used. In addition, by using a negative electrode made by adding 1 to 30% by weight of a carbonaceous material as a conductive material to the negative electrode material, it is possible to improve the conductivity as an electrode, and further improve the discharge capacity and cycle characteristics. Can be made. Examples of such added carbonaceous materials include carbon blacks such as acetylene black, thermal black, and furnace black. These may be used alone or in combination of two or more.
Lithium secondary battery By using the negative electrode for a lithium secondary battery of the present invention as a constituent element, a lithium secondary battery having a large charge / discharge capacity and a high initial efficiency can be produced. Specifically, a lithium secondary battery can be produced by a conventional method using the negative electrode of the present invention obtained by the above method as a constituent element, in combination with a positive electrode, an electrolyte (electrolyte), and the like.
[0009]
For example, LiCoO 2 , LiNiO 2 , LiMn 2 O 4, etc. can be used as the positive electrode binding material.
[0010]
By using an electrolytic solution in which an electrolyte is dissolved in an organic solvent, a non-aqueous lithium secondary battery can be manufactured. As the electrolyte, for example, it can be a salt which generates a LiPF 6, LiClO 4, LiBF 4 , LiAsF 6, LiSbF 6, LiAlO 4, LiAlCl 4, LiCl, hardly solvated such LiI anion.
[0011]
Examples of the organic solvent include propylene carbonate, ethylene carbonate, diethyl carbonate, gamma butyl lactone, tetrahydrofuran, 2-methyltetrahydrofuran, dioxolane, 4-methyldioxolane, sulfolane, 1,2-dimethoxyethane, dimethyl sulfoxide, acetonitrile, N , N-dimethylformamide, diethylene glycol, dimethyl ether and other aprotic solvents can be used alone or as a mixture of two or more.
When manufacturing a lithium secondary battery, together with the above negative electrode material, positive electrode material, and electrolytic solution, separators and collectors of polyolefin-based porous membranes including commonly used porous non-woven fabrics Using a battery component such as a gasket, a sealing plate, and a case, a lithium secondary battery in any form such as a cylindrical shape, a square shape, or a button shape can be produced according to a conventional method.
[0012]
【The invention's effect】
According to the present invention, it is possible to produce a carbonaceous material in which metal particles forming an alloy with lithium are uniformly dispersed in the pores of activated carbon particles. Such a carbonaceous material has excellent characteristics as a carbonaceous negative electrode material for a lithium secondary battery. Therefore, according to the present invention, a lithium secondary battery having a large charge / discharge capacity and high initial efficiency can be provided.
[0013]
【Example】
Hereinafter, the present invention will be described more specifically with reference to examples.
Example 1
* Manufacture of carbonaceous materials Impregnation / supporting treatment by stirring 1.1 g of pitch-based activated carbon fiber (specific surface area 700 m 2 / g) and 1 g of SnSO 4 in 500 mL of 0.01N dilute sulfuric acid for 2 hours and evaporating the solvent. Went.
[0014]
Next, after drying the impregnated / supported sample, in a normal heat treatment furnace, the temperature was increased to 1000 ° C. at a temperature increase rate of 10 ° C./min in an argon stream, and held at that temperature for 1 hour, Processed. The weight after firing was 1.2 g, and the ratio of Sn supported on activated carbon was determined to be 33% by weight in consideration of the yield of activated carbon fibers.
[0015]
The electrode was prepared by adding an NMP solution of binder (PVDF) to the heat-treated sample, adding 15% by weight of acetylene black based on the weight of the sample, and then applying it on the copper foil.
[0016]
The charge / discharge test uses a 1M solution of LiPF 6 / EC: DMC = 1: 1 as the counter electrode and the prepared electrode, LiPF 6 / EC: DMC = 1: 1, low current method (current density 0.5 mA / cm 2 ),
[0017]
The results are shown in Table 1 and FIG. Table 1 shows the results obtained in Example 2 and Comparative Examples 1 and 2 together. FIG. 1 shows the results obtained in Example 2 and Comparative Example 1 together.
Example 2
After obtaining a carbonaceous material in the same manner as in Example 1, an electrode coating was prepared in the same manner as in Example 1 except that acetylene black was not added, and an electrode evaluation test was conducted.
Comparative Example 1
After obtaining a carbonaceous material in the same manner as in Example 1 except that powdered Sn and pitch-based activated carbon fibers (specific surface area 700 m 2 / g) were mixed in a mortar, Example 1 except that acetylene black was not added. Similarly, an electrode coating was prepared and an electrode evaluation test was performed.
Comparative Example 2
Heat treatment and electrode coating preparation were performed in the same manner as in Example 1 except that pitch-based activated carbon fibers (specific surface area 700 m 2 / g) not supporting metal were used, and an electrode evaluation test was performed.
[0018]
[Table 1]
From the results shown in Table 1 and FIG. 1, it is clear that the negative electrode material according to the present invention has a large discharge capacity and little cycle deterioration.
[Brief description of the drawings]
FIG. 1 is a graph showing cycle characteristics of negative electrode materials obtained in Examples and Comparative Examples.
Claims (7)
(a)リチウムと合金を形成することができる金属の少なくとも１種、
(b)リチウムと合金を形成できる金属を含む２種以上の元素からなる合金の少なくとも１種、および
(c)リチウムと合金を形成することができる金属の酸化物、窒化物およびその他の化合物の少なくとも１種。(I) a step of obtaining an activated carbon-metal composite by impregnating and supporting at least one of the following metal components (a) to (c) in activated carbon particles in a solvent; and (II) the obtained activated carbon -A method for producing a carbonaceous material for a lithium secondary battery, comprising a step of heat-treating a metal composite at 800 to 1500 ° C ;
(a) at least one metal capable of forming an alloy with lithium;
(b) at least one alloy of two or more elements including a metal capable of forming an alloy with lithium, and
(c) At least one of metal oxides, nitrides and other compounds capable of forming an alloy with lithium.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32241499A JP4069465B2 (en) | 1999-11-12 | 1999-11-12 | Carbonaceous negative electrode material for lithium secondary battery and method for producing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32241499A JP4069465B2 (en) | 1999-11-12 | 1999-11-12 | Carbonaceous negative electrode material for lithium secondary battery and method for producing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2001143692A JP2001143692A (en) | 2001-05-25 |
| JP4069465B2 true JP4069465B2 (en) | 2008-04-02 |
Family
ID=18143408
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP32241499A Expired - Fee Related JP4069465B2 (en) | 1999-11-12 | 1999-11-12 | Carbonaceous negative electrode material for lithium secondary battery and method for producing the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4069465B2 (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9324996B2 (en) | 2010-08-10 | 2016-04-26 | Inter-University Research Institute Corporation National Institutes Of Natural Sciences | Carbon nanostructure, metal-supported carbon nanostructure, lithium-ion secondary battery, method for producing carbon nanostructure, and method for producing metal-supported carbon nanostructure |
| US10424786B1 (en) | 2018-12-19 | 2019-09-24 | Nexeon Limited | Electroactive materials for metal-ion batteries |
| US10508335B1 (en) | 2019-02-13 | 2019-12-17 | Nexeon Limited | Process for preparing electroactive materials for metal-ion batteries |
| US10964940B1 (en) | 2020-09-17 | 2021-03-30 | Nexeon Limited | Electroactive materials for metal-ion batteries |
| US11011748B2 (en) | 2018-11-08 | 2021-05-18 | Nexeon Limited | Electroactive materials for metal-ion batteries |
| US11165054B2 (en) | 2018-11-08 | 2021-11-02 | Nexeon Limited | Electroactive materials for metal-ion batteries |
| US11905593B2 (en) | 2018-12-21 | 2024-02-20 | Nexeon Limited | Process for preparing electroactive materials for metal-ion batteries |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100584671B1 (en) * | 2004-01-14 | 2006-05-30 | (주)케이에이치 케미컬 | Process for the preparation of carbon nanotube or carbon nanofiber electrodes by using sulfur or metal nanoparticle as a binder and electrode prepared thereby |
| US7531267B2 (en) | 2003-06-02 | 2009-05-12 | Kh Chemicals Co., Ltd. | Process for preparing carbon nanotube electrode comprising sulfur or metal nanoparticles as a binder |
| JP5032038B2 (en) * | 2006-02-28 | 2012-09-26 | 株式会社東芝 | Non-aqueous electrolyte battery electrode material, non-aqueous electrolyte battery and battery pack |
| JP2008198568A (en) * | 2007-02-15 | 2008-08-28 | China Steel Chemical Corp | Manufacturing method of negative electrode material for lithium secondary battery, negative electrode material for lithium secondary battery manufactured by manufacturing method, and lithium secondary battery using negative electrode material |
| US8361659B2 (en) * | 2008-06-20 | 2013-01-29 | Toyota Motor Engineering & Manufacturing North America, Inc. | Lithium-alloying-material/carbon composite |
-
1999
- 1999-11-12 JP JP32241499A patent/JP4069465B2/en not_active Expired - Fee Related
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9324996B2 (en) | 2010-08-10 | 2016-04-26 | Inter-University Research Institute Corporation National Institutes Of Natural Sciences | Carbon nanostructure, metal-supported carbon nanostructure, lithium-ion secondary battery, method for producing carbon nanostructure, and method for producing metal-supported carbon nanostructure |
| US11011748B2 (en) | 2018-11-08 | 2021-05-18 | Nexeon Limited | Electroactive materials for metal-ion batteries |
| US11165054B2 (en) | 2018-11-08 | 2021-11-02 | Nexeon Limited | Electroactive materials for metal-ion batteries |
| US11688849B2 (en) | 2018-11-08 | 2023-06-27 | Nexeon Limited | Electroactive materials for metal-ion batteries |
| US11695110B2 (en) | 2018-11-08 | 2023-07-04 | Nexeon Limited | Electroactive materials for metal-ion batteries |
| US10424786B1 (en) | 2018-12-19 | 2019-09-24 | Nexeon Limited | Electroactive materials for metal-ion batteries |
| US10658659B1 (en) | 2018-12-19 | 2020-05-19 | Nexeon Limited | Electroactive materials for metal-ion batteries |
| US10938027B2 (en) | 2018-12-19 | 2021-03-02 | Nexeon Limited | Electroactive materials for metal-ion batteries |
| US11715824B2 (en) | 2018-12-19 | 2023-08-01 | Nexeon Limited | Electroactive materials for metal-ion batteries |
| US11905593B2 (en) | 2018-12-21 | 2024-02-20 | Nexeon Limited | Process for preparing electroactive materials for metal-ion batteries |
| US10508335B1 (en) | 2019-02-13 | 2019-12-17 | Nexeon Limited | Process for preparing electroactive materials for metal-ion batteries |
| US10964940B1 (en) | 2020-09-17 | 2021-03-30 | Nexeon Limited | Electroactive materials for metal-ion batteries |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2001143692A (en) | 2001-05-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11145892B2 (en) | Surface-stabilized anode active material particulates for lithium batteries and production method | |
| JP4393610B2 (en) | Negative electrode material for lithium secondary battery, lithium secondary battery, and charging method of the secondary battery | |
| JP4861120B2 (en) | Negative electrode active material, production method thereof, and negative electrode and lithium battery employing the same | |
| US11664493B2 (en) | Negative electrode active material, negative electrode including the same and lithium secondary battery including the same | |
| US7629082B2 (en) | Anode active material with improved electrochemical properties and electrochemical device comprising the same | |
| US6156457A (en) | Lithium secondary battery and method for manufacturing a negative electrode | |
| US7674554B2 (en) | Anode active material, method of preparing the same, and anode and lithium battery containing the anode active material | |
| US20120045696A1 (en) | Negative electrode materials for non-aqueous electrolyte secondary battery | |
| US20110024676A1 (en) | Anode active material, method of preparing the same, and anode and lithium battery containing the material | |
| KR101666871B1 (en) | Positive electrode active material and method of manufacturing the same, and rechargeable lithium battery including the positive electrode active material | |
| KR101555932B1 (en) | Electrode active material for lithium secondary battery and Method of preparing the same | |
| JP2008282819A (en) | Manufacturing method of negative electrode active material for nonaqueous electrolyte secondary battery, and negative electrode active material for nonaqueous electrolyte secondary battery provided thereby | |
| KR20140044594A (en) | Positive active material layer composition for rechargeable lithium battery and rechargeable lithium battery using the same | |
| WO2023273917A1 (en) | Positive electrode material and preparation method therefor, and lithium ion battery | |
| WO2016136226A1 (en) | Method for manufacturing nonaqueous electrolyte secondary battery | |
| TW201545976A (en) | Method for manufacturing carbonaceous material for non-aqueous electrolyte secondary cell | |
| JP4069465B2 (en) | Carbonaceous negative electrode material for lithium secondary battery and method for producing the same | |
| US20130177815A1 (en) | Negative active material, lithium secondary battery comprising the negative active material and manufacturing method thereof | |
| JPH11233140A (en) | Nonaqueous electrolyte secondary battery | |
| KR102227102B1 (en) | Method for coating a lithium secondary battery electrode, and lithium secondary battery comprising a electrode using the same | |
| KR101551407B1 (en) | Negative electrode active material for rechargeable lithium battery, method for preparing the same, negative electrode including the same, and rechargeable lithium battery including the negative electrode | |
| US20220190328A1 (en) | Negative electrode for nonaqueous electrolyte secondary batteries | |
| JP3499739B2 (en) | Lithium secondary battery and method of manufacturing lithium secondary battery | |
| JP2022092077A (en) | Carbonaceous material for battery | |
| KR101553389B1 (en) | Positive active material for rechargeable lithium battery, coating material for positive active material, method of manufacturing the same and rechargeable lithium battery including same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20041202 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20060530 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20070620 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20070807 |
|
| 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: 20071212 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20080104 |
|
| R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110125 Year of fee payment: 3 |
|
| LAPS | Cancellation because of no payment of annual fees |