JP5169341B2 - Pre-charge / discharge method for lithium ion secondary battery and lithium ion secondary battery - Google Patents

Pre-charge / discharge method for lithium ion secondary battery and lithium ion secondary battery Download PDF

Info

Publication number
JP5169341B2
JP5169341B2 JP2008065881A JP2008065881A JP5169341B2 JP 5169341 B2 JP5169341 B2 JP 5169341B2 JP 2008065881 A JP2008065881 A JP 2008065881A JP 2008065881 A JP2008065881 A JP 2008065881A JP 5169341 B2 JP5169341 B2 JP 5169341B2
Authority
JP
Japan
Prior art keywords
positive electrode
ion secondary
secondary battery
lithium ion
lithium
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
Application number
JP2008065881A
Other languages
Japanese (ja)
Other versions
JP2009224119A (en
Inventor
博 佐和田
匠昭 奥田
厳 佐々木
良雄 右京
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toyota Central R&D Labs Inc
Original Assignee
Toyota Central R&D Labs Inc
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Toyota Central R&D Labs Inc filed Critical Toyota Central R&D Labs Inc
Priority to JP2008065881A priority Critical patent/JP5169341B2/en
Publication of JP2009224119A publication Critical patent/JP2009224119A/en
Application granted granted Critical
Publication of JP5169341B2 publication Critical patent/JP5169341B2/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

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
    • 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
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Description

本発明は、リチウムイオン二次電池の予備充放電方法及びリチウムイオン二次電池に関する。   The present invention relates to a preliminary charge / discharge method for a lithium ion secondary battery and a lithium ion secondary battery.

従来より、炭素質物質を負極活物質とする負極と、コバルト酸リチウム（ＬｉＣｏＯ2）を正極活物質とする正極と、正負極間でリチウムイオンを移動させるための非水電解液とを備えたリチウムイオン二次電池が知られている。こうしたリチウムイオン二次電池は、エネルギー密度や作動電圧が高く、自己放電が小さいという優れた利点を有している。その一方で、コバルトは希少金属なので高価なうえ、供給が不安定になりやすいという問題がある。このため、コバルト酸リチウムの代替候補として、リン酸鉄リチウム（ＬｉＦｅＰＯ4）などのオリビン型の結晶構造をとるリチウム複合酸化物が注目されている。特に、リン酸鉄リチウムは、資源として豊富な元素で構成されているのでコストが安価で安定供給が見込まれる。また、温度を上げても酸素を放出しにくい性質のため、高温での電解液との反応性が低く、電池の信頼性向上に寄与する材料としても期待されている。 Conventionally, a negative electrode using a carbonaceous material as a negative electrode active material, a positive electrode using lithium cobaltate (LiCoO 2 ) as a positive electrode active material, and a non-aqueous electrolyte for moving lithium ions between the positive and negative electrodes are provided. Lithium ion secondary batteries are known. Such a lithium ion secondary battery has an excellent advantage that the energy density and the operating voltage are high and the self-discharge is small. On the other hand, since cobalt is a rare metal, there is a problem that it is expensive and the supply tends to be unstable. For this reason, lithium composite oxides having an olivine type crystal structure such as lithium iron phosphate (LiFePO 4 ) are attracting attention as alternative candidates for lithium cobaltate. In particular, since lithium iron phosphate is composed of abundant elements as resources, the cost is low and stable supply is expected. In addition, since it is difficult to release oxygen even when the temperature is raised, the reactivity with the electrolytic solution at high temperature is low, and it is expected as a material that contributes to improving the reliability of the battery.

ところで、最近、リン酸鉄リチウムを正極活物質とするリチウムイオン二次電池に関して、充放電の履歴によって正極の入出力特性が変化することが報告された（非特許文献１参照）。この報告によれば、例えば、ＳＯＣ０％から充電してＳＯＣ５０％に調製した場合と、ＳＯＣ１００％から放電してＳＯＣ５０％に調製した場合とでは、どちらもＳＯＣ５０％のリチウムイオン二次電池であるにもかからわず、入出力特性が異なる。この報告では、その理由を次のように推察している。すなわち、ＳＯＣ０％から充電してＳＯＣ５０％に調製された場合には、図１に示すように、正極中の正極活物質はリン酸鉄リチウム（ＬｉＦｅＰＯ4）がコアとなりその表面にリン酸鉄（ＦｅＰＯ4）が存在すると考えられる。一方、ＳＯＣ１００％から放電してＳＯＣ５０％に調製された場合には、図２に示すように、正極中の正極活物質はリン酸鉄がコアとなりその表面にリン酸鉄リチウムが存在すると考えられる。そして、図１の状態で放電するとリチウムイオンは表面のリン酸鉄中に挿入されるのに対し、図２の状態で放電するとリチウムイオンは表面のリン酸鉄リチウムを通ってコアのリン酸鉄に挿入される。このため、図１の状態の方が図２の状態よりもリチウムイオンの移動距離が短くて済む。実際、同じＳＯＣ５０％の電池であっても、ＳＯＣ０％からＳＯＣ５０％に調製された場合の方がＳＯＣ１００％からＳＯＣ５０％に調製された場合に比べて放電容量が大きくなるが、これはリチウムイオンの移動距離が短いことによると考えられる。
Electrochemcal and Solid-State Letters, 9(3), A110-A114(2006)) By the way, recently, regarding a lithium ion secondary battery using lithium iron phosphate as a positive electrode active material, it has been reported that the input / output characteristics of the positive electrode change depending on the charge / discharge history (see Non-Patent Document 1). According to this report, for example, when the SOC is adjusted to 50% by charging from 0% SOC and when the SOC is adjusted to 50% by discharging from SOC 100%, both are lithium ion secondary batteries with 50% SOC. However, the input / output characteristics are different. In this report, the reason is presumed as follows. That is, when the SOC is adjusted from 0% to 50% SOC, the positive electrode active material in the positive electrode is composed of lithium iron phosphate (LiFePO 4 ) as a core and iron phosphate (Li FePO 4 ) is considered to be present. On the other hand, when the SOC is 100% and the SOC is adjusted to 50%, as shown in FIG. 2, the positive electrode active material in the positive electrode is considered to have iron phosphate as a core and lithium iron phosphate on the surface thereof. . When lithium ion is discharged in the state of FIG. 1, lithium ions are inserted into the iron phosphate on the surface, whereas when discharged in the state of FIG. 2, lithium ions pass through the lithium iron phosphate on the surface and the iron iron phosphate in the core. Inserted into. For this reason, the movement distance of lithium ions in the state of FIG. 1 is shorter than that in the state of FIG. In fact, even if the batteries have the same SOC 50%, the discharge capacity is larger when the SOC is adjusted from 0% to SOC 50% than when the SOC is adjusted from 100% SOC to 50% SOC. This is thought to be due to the short travel distance.
(Electrochemcal and Solid-State Letters, 9 (3), A110-A114 (2006))

しかしながら、リチウムイオン二次電池において、同じＳＯＣであってもそれまでの充放電履歴によって放電容量が変化するのは、電池寿命の予測が困難になるため好ましくない。特に、電動工具などのパワーツールやハイブリッド自動車などのモータ搭載車両のように高出力が要求される装置においては、予想外の電池切れが起こるのは好ましくない。   However, in a lithium ion secondary battery, even if the SOC is the same, it is not preferable that the discharge capacity changes due to the charge / discharge history so far because it becomes difficult to predict the battery life. In particular, in an apparatus that requires high output, such as a power tool such as an electric tool or a motor-equipped vehicle such as a hybrid vehicle, it is not preferable that the battery runs out unexpectedly.

本発明はこのような問題を解決するためになされたものであり、オリビン型構造のリチウム複合酸化物を正極活物質とするリチウムイオン二次電池において、同じＳＯＣであっても充放電の履歴により放電容量が変化してしまうのを抑制することを主目的とする。   The present invention has been made to solve such a problem. In a lithium ion secondary battery using an olivine type lithium composite oxide as a positive electrode active material, even if the SOC is the same, the charge / discharge history is used. The main purpose is to prevent the discharge capacity from changing.

上述した目的を達成するために、本発明者らは、オリビン型構造のリチウム複合酸化物を正極活物質とするリチウムイオン二次電池を組み立てた直後に、充電終止時の正極の電位がリチウム金属に対して４．１Ｖ、放電終止時の正極の電位がリチウム金属に対して２．５Ｖとなる充放電を２Ｃレートで５００サイクル繰り返し実行する予備充放電を行ったところ、その後同じＳＯＣであれば充放電の履歴によらず放電容量がほとんど変化しないことを見いだし、本発明を完成するに至った。   In order to achieve the above-described object, the inventors of the present invention immediately after assembling a lithium ion secondary battery using an olivine-type lithium composite oxide as a positive electrode active material, the potential of the positive electrode at the end of charging is lithium metal. When the precharge / discharge in which the charge / discharge at which the positive electrode potential at the end of the discharge becomes 2.5V with respect to the lithium metal is repeatedly performed for 500 cycles at a 2C rate is performed, The inventors have found that the discharge capacity hardly changes regardless of the charge / discharge history, and have completed the present invention.

即ち、本発明の予備充放電方法は、負極と、オリビン型構造のリチウム複合酸化物を正極活物質とする正極と、前記負極と前記正極との間に介在する非水系電解液とを備えたリチウムイオン二次電池の予備充放電方法であって、電池組立直後に、充電終止時の正極の電位がリチウム金属に対して３．５〜５．０Ｖ、放電終止時の正極の電位がリチウム金属に対して０〜３．３Ｖとなる充放電を２Ｃレート以上で繰り返し実行するものである。   That is, the pre-charging / discharging method of the present invention includes a negative electrode, a positive electrode using a lithium composite oxide having an olivine structure as a positive electrode active material, and a non-aqueous electrolyte solution interposed between the negative electrode and the positive electrode. A method for precharging and discharging a lithium ion secondary battery, wherein the potential of the positive electrode at the end of charging is 3.5 to 5.0 V with respect to lithium metal immediately after battery assembly, and the potential of the positive electrode at the end of discharging is lithium metal. In contrast, charging / discharging at 0 to 3.3 V is repeatedly performed at a rate of 2C or higher.

また、本発明のリチウムイオン二次電池は、負極と、オリビン型構造のリチウム複合酸化物を正極活物質とする正極と、前記負極と前記正極との間に介在する非水系電解液とを備えたリチウムイオン二次電池であって、ＳＯＣ０％から充電してＳＯＣ５０％に調製したあと電池を放電させたときの放電容量をＸ、ＳＯＣ１００％から放電してＳＯＣ５０％に調製したあと電池を放電させたときの放電容量をＹとしたときの評価指数Ｚ＝１００×Ｙ／Ｘ（％）が９０％以上のものである。   The lithium ion secondary battery of the present invention includes a negative electrode, a positive electrode using a lithium composite oxide having an olivine structure as a positive electrode active material, and a non-aqueous electrolyte solution interposed between the negative electrode and the positive electrode. The lithium ion secondary battery was charged from SOC 0% and adjusted to SOC 50%, and then the battery was discharged. After discharging the battery from X and SOC 100% to SOC 50%, the battery was discharged. The evaluation index Z = 100 × Y / X (%) when the discharge capacity is Y is 90% or more.

本発明の予備充放電方法によれば、オリビン型構造のリチウム複合酸化物を正極活物質とするリチウムイオン二次電池において、同じＳＯＣであっても充放電の履歴により放電容量が変化してしまうのを抑制することができる。こうした効果が得られる理由は定かではないが、予備的な充電だけでなく放電も行うことで、正極活物質であるオリビン型構造のリチウム複合酸化物に何らかの特異的な変化が生じ、同じＳＯＣでも充放電履歴によって正極活物質で表裏二層に分かれる現象（図１及び図２参照）が生じにくくなったためと推察される。   According to the preliminary charge / discharge method of the present invention, in a lithium ion secondary battery using an olivine-type lithium composite oxide as a positive electrode active material, the discharge capacity varies depending on the charge / discharge history even if the SOC is the same. Can be suppressed. The reason why such an effect is obtained is not clear, but by performing not only preliminary charging but also discharging, some specific change occurs in the lithium composite oxide of the olivine type structure that is the positive electrode active material, and even in the same SOC This is presumably because the phenomenon (see FIGS. 1 and 2) in which the positive electrode active material divides into two layers is less likely to occur due to the charge / discharge history.

こうした予備充放電方法を施したリチウムイオン二次電池は、ＳＯＣ０％から充電してＳＯＣ５０％に調製したあと電池を放電させたときの放電容量をＸ、ＳＯＣ１００％から放電してＳＯＣ５０％に調製したあと電池を放電させたときの放電容量をＹとしたときの評価指数Ｚ＝１００×Ｙ／Ｘ（％）が９０％以上になる。このため、電池寿命を精度よく予測することができ、電動工具などのパワーツールやハイブリッド自動車などのモータ搭載車両のように高出力が要求される装置において予想外の電池切れが起きるのを防止することができる。   In the lithium ion secondary battery subjected to such a pre-charge / discharge method, the discharge capacity when discharging the battery from X, SOC 100% was adjusted to 50% SOC when the battery was discharged after being charged from 0% SOC to 50% SOC. The evaluation index Z = 100 × Y / X (%) when the discharge capacity when the battery is discharged is Y is 90% or more. For this reason, battery life can be accurately predicted, and unexpected battery exhaustion can be prevented in devices that require high output, such as power tools such as electric tools and motor-equipped vehicles such as hybrid vehicles. be able to.

本発明のリチウムイオン二次電池の予備充放電方法は、負極と、オリビン型構造のリチウム複合酸化物を正極活物質とする正極と、前記負極と前記正極との間に介在する非水系電解液とを備えたリチウムイオン二次電池の予備充放電方法であって、電池組立直後に、充電終止時の正極の電位がリチウム金属に対して３．５〜５．０Ｖ、放電終止時の正極の電位がリチウム金属に対して０〜３．３Ｖとなる充放電を２Ｃレート以上で繰り返し実行するものである。   A method for precharging and discharging a lithium ion secondary battery according to the present invention includes a negative electrode, a positive electrode using a lithium composite oxide having an olivine structure as a positive electrode active material, and a nonaqueous electrolytic solution interposed between the negative electrode and the positive electrode A lithium ion secondary battery pre-charging / discharging method comprising: immediately after battery assembly, the potential of the positive electrode at the end of charging is 3.5 to 5.0 V with respect to lithium metal; Charging / discharging at a potential of 0 to 3.3 V with respect to lithium metal is repeatedly performed at a 2C rate or higher.

オリビン型構造のリチウム複合酸化物を正極活物質とする正極は、３．４Ｖ付近に電位平坦部を有するので、充電終止時の正極の電位はリチウム金属に対して３．５〜５．０Ｖ、好ましくは３．９〜４．３Ｖとし、放電終止時の正極の電位はリチウム金属に対して０〜３．３Ｖ、好ましくは２．３〜２．７Ｖとする。充電終止時の正極の電位をリチウム金属に対して３．５Ｖ以上としたのは電位平坦部である３．４Ｖ付近を上回るようにして確実に充電できるようにするためであり、５．０Ｖ以下としたのは非水系電解液が酸化分解してしまうことのないようにするためである。また、放電終止時の正極の電位をリチウム金属に対して３．３Ｖ以下としたのは電位平坦部である３．４Ｖ付近を下回るようにして十分放電できるようにするためであり、０Ｖ以上としたのは電極へのリチウムの析出が起きないようにするためである。   Since the positive electrode using the lithium composite oxide having an olivine structure as the positive electrode active material has a potential flat portion in the vicinity of 3.4 V, the potential of the positive electrode at the end of charging is 3.5 to 5.0 V with respect to lithium metal, Preferably, it is 3.9 to 4.3 V, and the potential of the positive electrode at the end of discharge is 0 to 3.3 V, preferably 2.3 to 2.7 V with respect to lithium metal. The positive electrode potential at the end of charging was set to 3.5 V or higher with respect to lithium metal in order to ensure that charging can be performed by exceeding the vicinity of 3.4 V, which is a flat potential portion. The reason for this is to prevent the non-aqueous electrolyte from being oxidized and decomposed. In addition, the positive electrode potential at the end of discharge was set to 3.3 V or less with respect to lithium metal in order to ensure sufficient discharge so that it is below 3.4 V, which is a flat potential portion. This is to prevent lithium from being deposited on the electrode.

本発明のリチウムイオン二次電池の予備充放電方法は、充放電速度を２Ｃレート以上とする。充放電速度が低すぎると、同じＳＯＣのときに充放電の履歴により放電容量が変化してしまうのを抑制できないことがあるからである。   In the preliminary charge / discharge method of the lithium ion secondary battery of the present invention, the charge / discharge rate is set to a 2C rate or higher. This is because if the charge / discharge rate is too low, it may not be possible to suppress the change in discharge capacity due to the charge / discharge history at the same SOC.

本発明のリチウムイオン二次電池の予備充放電方法は、充放電の繰り返しサイクル数は、特に限定されないが、５〜１０００サイクルが好ましく、１０〜７００サイクルがより好ましい。５サイクル以上としたのは本発明の効果を確実に得るためであり、１０００サイクル以下としたのはそれを超えると予備充放電に時間がかかりすぎて好ましくないためである。また、充放電の温度は、特に限定されないが、例えば０〜８０℃が好ましく、２０〜６０℃がより好ましい。０℃を下回ったり８０℃を上回ると電池の劣化が懸念されるためである。   In the preliminary charge / discharge method of the lithium ion secondary battery of the present invention, the number of charge / discharge cycles is not particularly limited, but is preferably 5 to 1000 cycles, more preferably 10 to 700 cycles. The reason why the number of cycles is 5 or more is to ensure the effect of the present invention, and that the number of cycles is 1000 or less is that it is not preferable because precharging / discharging takes too much time. Moreover, although the temperature of charging / discharging is not specifically limited, For example, 0-80 degreeC is preferable and 20-60 degreeC is more preferable. This is because if the temperature is lower than 0 ° C. or exceeds 80 ° C., the battery may be deteriorated.

本発明のリチウムイオン二次電池は、負極と、オリビン型構造のリチウム複合酸化物を正極活物質とする正極と、前記負極と前記正極との間に介在する非水系電解液とを備えたリチウムイオン二次電池であって、ＳＯＣ０％から充電してＳＯＣ５０％に調製したあと電池を放電させたときの放電容量をＸ、ＳＯＣ１００％から放電してＳＯＣ５０％に調製したあと電池を放電させたときの放電容量をＹとしたときの評価指数Ｚ＝１００×Ｙ／Ｘ（％）が９０％以上のものである。こうしたリチウムイオン二次電池は、本発明の予備充放電方法を実行することにより得られるものである。すなわち、電池組立直後に本発明の予備充放電方法を実行しなかった場合には、評価指数Ｚが９０％未満であるのに対して、電池組立直後に本発明の予備充放電方法を実行した場合には、評価指数Ｚが９０％以上になり、電池寿命の予測が容易になる。評価指数Ｚは９５％以上であることが、電池寿命の予測をより正確に行ううえで好ましい。評価指数Ｚを９５％以上とするには、例えば、非水系電解液にビニレンカーボネート（ＶＣ）が添加されたカーボネート系溶媒にリチウム支持塩を溶解させた電解液を用いたり、予備充放電の温度を６０℃前後に設定したりすることが挙げられる。   A lithium ion secondary battery according to the present invention includes a negative electrode, a positive electrode using a lithium composite oxide having an olivine structure as a positive electrode active material, and a non-aqueous electrolyte solution interposed between the negative electrode and the positive electrode. When an ion secondary battery is charged from SOC 0% and adjusted to SOC 50% and then discharged, the discharge capacity is X, when discharged from 100% SOC and adjusted to SOC 50% and then discharged. When the discharge capacity is Y, the evaluation index Z = 100 × Y / X (%) is 90% or more. Such a lithium ion secondary battery is obtained by executing the preliminary charge / discharge method of the present invention. That is, when the preliminary charging / discharging method of the present invention is not performed immediately after battery assembly, the evaluation index Z is less than 90%, whereas the preliminary charging / discharging method of the present invention is performed immediately after battery assembly. In this case, the evaluation index Z is 90% or more, and the battery life can be easily predicted. The evaluation index Z is preferably 95% or more in order to more accurately predict the battery life. In order to make the evaluation index Z 95% or more, for example, an electrolyte solution in which a lithium-supported salt is dissolved in a carbonate solvent in which vinylene carbonate (VC) is added to a non-aqueous electrolyte solution is used, or a temperature for pre-charging and discharging is used. Is set to around 60 ° C.

本発明で用いるリチウムイオン二次電池において、負極は、充電時にリチウムイオンを放出し放電時にリチウムイオンを吸蔵可能な負極活物質を含むものであれば特に限定されない。ここで、負極活物質としては、例えばリチウムイオンを吸蔵放出可能な炭素質物質が挙げられる。こうした炭素質物質としては、例えば天然黒鉛、人造黒鉛、コークス、メソフェーズピッチ系炭素繊維、球状炭素、樹脂焼成炭素などが挙げられる。   In the lithium ion secondary battery used in the present invention, the negative electrode is not particularly limited as long as it includes a negative electrode active material capable of releasing lithium ions during charging and storing lithium ions during discharging. Here, examples of the negative electrode active material include a carbonaceous material capable of occluding and releasing lithium ions. Examples of such a carbonaceous material include natural graphite, artificial graphite, coke, mesophase pitch carbon fiber, spherical carbon, and resin-fired carbon.

本発明で用いるリチウムイオン二次電池において、正極は、オリビン型構造のリチウム複合酸化物を正極活物質とするものである。こうしたリチウム複合酸化物としては、例えばリン酸鉄リチウム（ＬｉＦｅＰＯ4）やリン酸マンガンリチウム（ＬｉＭｎＰＯ4）、リン酸コバルトリチウム（ＬｉＣｏＰＯ4）、リン酸ニッケルリチウム（ＬｉＮｉＰＯ4）などが挙げられるが、このうちリン酸鉄リチウムが好ましい。リン酸鉄リチウムは、資源として豊富な元素で構成されているのでコストが安価で安定供給が見込まれるばかりでなく、温度を上げても酸素を放出しにくい性質のため高温での電解液との反応性が低いからである。 In the lithium ion secondary battery used in the present invention, the positive electrode uses an olivine type lithium composite oxide as the positive electrode active material. Examples of such lithium composite oxides include lithium iron phosphate (LiFePO 4 ), lithium manganese phosphate (LiMnPO 4 ), lithium cobalt phosphate (LiCoPO 4 ), and lithium nickel phosphate (LiNiPO 4 ). Of these, lithium iron phosphate is preferred. Lithium iron phosphate is composed of abundant elements as a resource, so it is not only cheap and stable supply is expected, but it is difficult to release oxygen even when the temperature is raised. This is because the reactivity is low.

本発明で用いるリチウムイオン二次電池において、正極及び負極は、導電材を含んでいてもよい。導電材としては、導電性を有する材料であれば特に限定されない。例えば、ケッチェンブラックやアセチレンブラック、チャンネルブラック、ファーネスブラック、ランプブラック、サーマルブラック等のカーボンブラック類でもよいし、鱗片状黒鉛のような天然黒鉛や人造黒鉛、膨張黒鉛などのグラファイト類でもよいし、炭素繊維や金属繊維などの導電性繊維類でもよいし、銅や銀、ニッケル、アルミニウムなどの金属粉末類でもよいし、ポリフェニレン誘導体などの有機導電性材料でもよい。また、これらを単体で用いてもよいし、複数を混合して用いてもよい。   In the lithium ion secondary battery used in the present invention, the positive electrode and the negative electrode may contain a conductive material. The conductive material is not particularly limited as long as it is a conductive material. For example, carbon blacks such as ketjen black, acetylene black, channel black, furnace black, lamp black and thermal black may be used, and natural graphite such as flake graphite, graphite such as artificial graphite and expanded graphite may be used. Further, conductive fibers such as carbon fibers and metal fibers, metal powders such as copper, silver, nickel, and aluminum, or organic conductive materials such as polyphenylene derivatives may be used. These may be used alone or in combination.

本発明で用いるリチウムイオン二次電池において、正極及び負極は、バインダを含んでいてもよい。バインダとしては、特に限定されるものではないが、熱可塑性樹脂や熱硬化性樹脂などが挙げられる。例えば、ポリエチレン、ポリプロピレン、ポリテトラフルオロエチレン（ＰＴＦＥ）、ポリフッ化ビニリデン（ＰＶＤＦ）、スチレンブタジエンゴム、フッ素ゴム、テトラフルオロエチレン−ヘキサフルオロエチレン共重合体、テトラフルオロエチレン−ヘキサフルオロプロピレン共重合体（ＦＥＰ）、テトラフルオロエチレン−パーフルオロアルキルビニルエーテル共重合体（ＰＦＡ）、フッ化ビニリデン−ヘキサフルオロプロピレン共重合体、フッ化ビニリデン−クロロトリフルオロエチレン共重合体、エチレン−テトラフルオロエチレン共重合体（ＥＴＦＥ樹脂）、ポリクロロトリフルオロエチレン（ＰＣＴＦＥ）、フッ化ビニリデン−ペンタフルオロプロピレン共重合体、プロピレン−テトラフルオロエチレン共重合体、エチレン−クロロトリフルオロエチレン共重合体（ＥＣＴＦＥ）、フッ化ビニリデン−ヘキサフルオロプロピレン−テトラフルオロエチレン共重合体、フッ化ビニリデン−パーフルオロメチルビニルエーテル−テトラフルオロエチレン共重合体、エチレン−アクリル酸共重合体などが挙げられる。これらの材料は単独で用いてもよいし、複数を混合して用いてもよい。   In the lithium ion secondary battery used in the present invention, the positive electrode and the negative electrode may contain a binder. Although it does not specifically limit as a binder, A thermoplastic resin, a thermosetting resin, etc. are mentioned. For example, polyethylene, polypropylene, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), styrene butadiene rubber, fluoro rubber, tetrafluoroethylene-hexafluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer ( FEP), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-chlorotrifluoroethylene copolymer, ethylene-tetrafluoroethylene copolymer ( ETFE resin), polychlorotrifluoroethylene (PCTFE), vinylidene fluoride-pentafluoropropylene copolymer, propylene-tetrafluoroethylene copolymer, ethylene- Rollotrifluoroethylene copolymer (ECTFE), vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene copolymer, vinylidene fluoride-perfluoromethyl vinyl ether-tetrafluoroethylene copolymer, ethylene-acrylic acid copolymer, etc. Is mentioned. These materials may be used alone or in combination.

本発明で用いるリチウムイオン二次電池において、正極及び負極は、正極活物質又は負極活物質と導電材とバインダとを所定の配合比で混合した後、集電体にプレス成形して形成してもよい。混合方法としては、メタノールなどの溶媒存在下で湿式混合してもよいし、乳鉢などを使って乾式混合してもよい。なお、集電体としては、特に限定するものではないが、例えば、ステンレス鋼やアルミニウム、銅などの金属板や金属メッシュを用いてもよい。あるいは、ＩｎＳｎＯ2やＳｎＯ2，ＺｎＯ，Ｉｎ2Ｏ2などの透明導電材を用いてもよいし、フッ素ドープ酸化錫（ＳｎＯ2：Ｆ）やアンチモンドープ酸化錫（ＳｎＯ2：Ｓｂ）、錫ドープ酸化インジウム（Ｉｎ2Ｏ3：Ｓｎ）、ＺｎＯ，Ａｌドープ酸化亜鉛（ＺｎＯ：Ａｌ）、Ｇａドープ酸化亜鉛（ＺｎＯ：Ｇａ）などの不純物がドープされた材料等の単層又は積層層を、ガラスや高分子状に形成させたものを用いてもよい。 In the lithium ion secondary battery used in the present invention, the positive electrode and the negative electrode are formed by mixing the positive electrode active material or the negative electrode active material, the conductive material, and the binder at a predetermined blending ratio, and then press-molding the current collector. Also good. As a mixing method, wet mixing may be performed in the presence of a solvent such as methanol, or dry mixing may be performed using a mortar or the like. In addition, although it does not specifically limit as a collector, For example, you may use metal plates and metal meshes, such as stainless steel, aluminum, and copper. Alternatively, a transparent conductive material such as InSnO 2 , SnO 2 , ZnO, In 2 O 2 may be used, fluorine-doped tin oxide (SnO 2 : F), antimony-doped tin oxide (SnO 2 : Sb), tin-doped A single layer or a laminated layer made of an impurity-doped material such as indium oxide (In 2 O 3 : Sn), ZnO, Al-doped zinc oxide (ZnO: Al), or Ga-doped zinc oxide (ZnO: Ga) is formed of glass. Alternatively, those formed in a polymer form may be used.

本発明で用いるリチウムイオン二次電池において、非水系電解液は、特に限定されるものではないが、例えば、支持塩を有機溶媒に溶解させたものを用いることができる。支持塩としては、例えば、ＬｉＰＦ6，ＬｉＣｌＯ4，ＬｉＢＦ4，Ｌｉ（ＣＦ3ＳＯ3）、ＬｉＡｓＦ6、ＬｉＮ（ＣＦ3ＳＯ2）2、ＬｉＮ（Ｃ2Ｆ5ＳＯ2）などの公知の支持塩を用いることができる。有機溶媒としては、例えば、環状カーボネート、鎖状カーボネート、環状エステル、環状エーテル、鎖状エーテル等が挙げられる。環状カーボネートとしては、例えばエチレンカーボネート（ＥＣ）、プロピレンカーボネート（ＰＣ）、ブチレンカーボネート（ＢＣ）、ビニレンカーボネート（ＶＣ）等がある。鎖状カーボネートとしては、例えばジメチルカーボネート（ＤＭＣ）、ジエチルカーボネート（ＤＥＣ）、メチルエチルカーボネート等がある。環状エステルカーボネートとしては、例えばガンマブチロラクトン、ガンマバレロラクトン等がある。環状エーテルとしては、例えばテトラヒドロフラン、２−メチルテトラヒドロフラン等がある。鎖状エーテルとしては、例えばジメトキシエタン、エチレングリコールジメチルエーテル等が挙げられる。これらは単独で用いてもよいし、複数を混合して用いてもよい。これらの有機溶媒のうち、本発明では、ＶＣを添加したカーボネート系溶媒を用いることが好ましい。ＶＣを添加すると、添加しない場合に比べて本発明の効果が顕著になるからである。このＶＣの添加量は、ＶＣ以外のカーボネート系溶媒に対して０．１〜１０体積％であることが好ましい。また、ＶＣ以外のカーボネート系溶媒としては、特に限定されないが、例えばＥＣとＤＥＣとの混合溶媒が好ましい。 In the lithium ion secondary battery used in the present invention, the non-aqueous electrolyte solution is not particularly limited, but for example, a solution obtained by dissolving a supporting salt in an organic solvent can be used. Examples of the supporting salt include known supports such as LiPF 6 , LiClO 4 , LiBF 4 , Li (CF 3 SO 3 ), LiAsF 6 , LiN (CF 3 SO 2 ) 2 , and LiN (C 2 F 5 SO 2 ). A salt can be used. Examples of the organic solvent include cyclic carbonate, chain carbonate, cyclic ester, cyclic ether, chain ether and the like. Examples of the cyclic carbonate include ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), and vinylene carbonate (VC). Examples of the chain carbonate include dimethyl carbonate (DMC), diethyl carbonate (DEC), and methyl ethyl carbonate. Examples of the cyclic ester carbonate include gamma butyrolactone and gamma valerolactone. Examples of the cyclic ether include tetrahydrofuran and 2-methyltetrahydrofuran. Examples of the chain ether include dimethoxyethane and ethylene glycol dimethyl ether. These may be used alone or in combination. Among these organic solvents, in the present invention, it is preferable to use a carbonate-based solvent to which VC is added. This is because when VC is added, the effect of the present invention becomes more significant than when VC is not added. It is preferable that the addition amount of this VC is 0.1-10 volume% with respect to carbonate type solvents other than VC. Moreover, it is although it does not specifically limit as carbonate type solvents other than VC, For example, the mixed solvent of EC and DEC is preferable.

本発明で用いるリチウムイオン二次電池は、負極と正極との間にセパレータを備えていてもよい。セパレータとしては、リチウムイオン二次電池の使用範囲に耐えうる組成であれば特に限定されないが、例えば、ポリプロピレン製不織布やポリフェニレンスルフィド製不織布などの高分子不織布、ポリエチレンやポリプロピレンなどのオレフィン系樹脂の薄い微多孔膜が挙げられる。これらは単独で用いてもよいし、複数を混合して用いてもよい。   The lithium ion secondary battery used in the present invention may include a separator between the negative electrode and the positive electrode. The separator is not particularly limited as long as the composition can withstand the use range of the lithium ion secondary battery. For example, a polymer nonwoven fabric such as a polypropylene nonwoven fabric or a polyphenylene sulfide nonwoven fabric, or a thin olefin resin such as polyethylene or polypropylene is used. A microporous membrane is mentioned. These may be used alone or in combination.

本発明で用いるリチウムイオン二次電池の形状は、特に限定されないが、例えばコイン型、ボタン型、シート型、積層型、円筒型、偏平型、角型などが挙げられる。また、こうしたリチウムイオン二次電池を複数直列に接続して電気自動車用電源としてもよい。電気自動車としては、例えば、電池のみで駆動する電池電気自動車や内燃機関とモータ駆動とを組み合わせたハイブリッド電気自動車、燃料電池で発電する燃料電池自動車等が挙げられる。   The shape of the lithium ion secondary battery used in the present invention is not particularly limited, and examples thereof include a coin type, a button type, a sheet type, a laminated type, a cylindrical type, a flat type, and a square type. Further, a plurality of such lithium ion secondary batteries may be connected in series to serve as an electric vehicle power source. Examples of the electric vehicle include a battery electric vehicle driven only by a battery, a hybrid electric vehicle combining an internal combustion engine and a motor drive, a fuel cell vehicle generating power by a fuel cell, and the like.

［実施例１］
本実施例では、正極活物質としてオリビン構造のリン酸鉄リチウムＬｉＦｅＰＯ4を含む正極シート電極と、負極活物質として黒鉛を含む負極シート電極とを備えたリチウムイオン二次電池を作製した。 [Example 1]
In this example, a lithium ion secondary battery including a positive electrode sheet electrode containing olivine lithium iron phosphate LiFePO 4 as a positive electrode active material and a negative electrode sheet electrode containing graphite as a negative electrode active material was produced.

まず、正極シート電極を以下のようにして作製した。すなわち、正極活物質としてオリビン構造のリン酸鉄リチウムＬｉＦｅＰＯ4を、導電助材としてカーボンブラック（東海カーボン製のＴＢ５５００）を、バインダとしてポリフッ化ビニリデン（クレハ製のＫＦポリマー）を用い、正極活物質／導電助材／バインダを７８．５／１３．８／７．７（重量％）で混合し、正極合材を得た。この正極合材をＮ−メチル−２−ピロリドン（ＮＭＰ）で分散させたペーストを、厚さ２０μｍのアルミニウム箔の両面に途工乾燥させ、ロールプレスしたものを正極シート電極とした。なお、正極シート電極は５４ｍｍ×４５０ｍｍである。 First, the positive electrode sheet electrode was produced as follows. That is, lithium iron phosphate LiFePO 4 having an olivine structure as a positive electrode active material, carbon black (TB5500 manufactured by Tokai Carbon Co., Ltd.) as a conductive additive, and polyvinylidene fluoride (KF polymer manufactured by Kureha) as a binder. / Conductive aid / binder was mixed at 78.5 / 13.8 / 7.7 (% by weight) to obtain a positive electrode mixture. A paste in which this positive electrode mixture was dispersed with N-methyl-2-pyrrolidone (NMP) was dried on both sides of an aluminum foil having a thickness of 20 μm and roll-pressed to obtain a positive electrode sheet electrode. The positive electrode sheet electrode is 54 mm × 450 mm.

また、負極シート電極を以下のようにして作製した。負極活物質として黒鉛（大阪ガス製のＭＣＭＢ）を、バインダとして前出のポリフッ化ビニリデンを用い、それぞれ９５／５（重量％）で混合し、負極合材を得た。この負極合材をＮＭＰで分散させたペーストを、厚さ１０μｍ銅箔の両面に途工乾燥させ、ロールプレスしたものを負極シート電極とした。なお、負極シート電極は５６ｍｍ×５００ｍｍである。   Moreover, the negative electrode sheet electrode was produced as follows. Graphite (MCMB manufactured by Osaka Gas Co., Ltd.) was used as the negative electrode active material, and the above-mentioned polyvinylidene fluoride was used as the binder, and each was mixed at 95/5 (% by weight) to obtain a negative electrode mixture. A paste in which this negative electrode mixture was dispersed with NMP was dried on both sides of a 10 μm thick copper foil and roll-pressed to obtain a negative electrode sheet electrode. In addition, the negative electrode sheet electrode is 56 mm x 500 mm.

このようにして作製した正極シート電極及び負極シート電極をセパレータ（東燃タピルス製、ポリエチレン製２５μｍ厚、幅５８ｍｍのもの）を介してロール状に捲回し、１８６５０電池缶に挿入し、電解液を注入した後に、トップキャップをかしめて密閉することにより、リチウムイオン二次電池を作製した。電解液は、ＥＣとＤＥＣとの体積比３：７の混合溶媒に六フッ化リン酸リチウム（ＬｉＰＦ6）を濃度が１Ｍとなるように溶解したものを用いた。そして、電池組立直後に予備充放電を行った。予備充放電は、２０℃、２Ｃレートで、充電終止時の正極が４．１Ｖ（リチウム金属に対する電位、以下同じ）、放電終止時の正極が２．５Ｖとなるようにする充放電を１サイクルとし、これを５００サイクル繰り返し実行した。なお、充電後及び放電後の休止時間は１０分とした。こうした予備充放電を行ったあとのリチウムイオン二次電池を、実施例１のリチウムイオン二次電池とした。 The positive electrode sheet electrode and the negative electrode sheet electrode thus produced are wound into a roll through a separator (made of Tonen Tapirs, polyethylene, 25 μm thick, 58 mm wide), inserted into a 18650 battery can, and injected with an electrolyte. After that, the lithium ion secondary battery was produced by caulking the top cap and sealing it. As the electrolytic solution, a solution in which lithium hexafluorophosphate (LiPF 6 ) was dissolved in a mixed solvent of EC and DEC in a volume ratio of 3: 7 so as to have a concentration of 1M was used. Then, preliminary charging / discharging was performed immediately after battery assembly. Pre-charging / discharging is one cycle of charging / discharging so that the positive electrode at the end of charging is 4.1 V (potential with respect to lithium metal, the same applies hereinafter) and the positive electrode at the end of discharging is 2.5 V at 20 ° C. and 2C rate. This was repeated 500 cycles. The rest time after charging and discharging was 10 minutes. The lithium ion secondary battery after performing such preliminary charging / discharging was used as the lithium ion secondary battery of Example 1.

［実施例２］
実施例２のリチウムイオン二次電池は、予備充放電を６０℃で実施した以外は、実施例１のリチウムイオン二次電池と同様にして作製した。 [Example 2]
The lithium ion secondary battery of Example 2 was produced in the same manner as the lithium ion secondary battery of Example 1, except that the preliminary charge / discharge was performed at 60 ° C.

［実施例３］
実施例３のリチウムイオン二次電池は、電解液として、ＥＣとＤＥＣとの体積比３：７の混合溶媒にＶＣを１００：１の体積比で混合したものに六フッ化リン酸リチウム（ＬｉＰＦ6）を濃度が１Ｍとなるように溶解したものを用いた以外は、実施例１のリチウムイオン二次電池と同様にして作製した。 [Example 3]
The lithium ion secondary battery of Example 3 was obtained by mixing lithium hexafluorophosphate (LiPF) into a mixed solvent of EC and DEC in a volume ratio of 3: 7 mixed with VC at a volume ratio of 100: 1. 6 ) A lithium ion secondary battery of Example 1 was prepared in the same manner as in Example 1 except that a solution in which the concentration was 1M was used.

［実施例４］
実施例４のリチウムイオン二次電池は、予備充放電を６０℃で実施した以外は、実施例３のリチウムイオン二次電池と同様にして作製した。 [Example 4]
The lithium ion secondary battery of Example 4 was produced in the same manner as the lithium ion secondary battery of Example 3, except that the preliminary charge / discharge was performed at 60 ° C.

［比較例１］
比較例１のリチウムイオン二次電池は、予備充放電を行わなかったこと以外は、実施例１のリチウムイオン二次電池と同様にして作製した。 [Comparative Example 1]
The lithium ion secondary battery of Comparative Example 1 was produced in the same manner as the lithium ion secondary battery of Example 1 except that the preliminary charge / discharge was not performed.

［比較例２］
比較例２のリチウムイオン二次電池は、予備充放電を行わなかったこと以外は、実施例３のリチウムイオン二次電池と同様にして作製した。 [Comparative Example 2]
The lithium ion secondary battery of Comparative Example 2 was produced in the same manner as the lithium ion secondary battery of Example 3 except that preliminary charge / discharge was not performed.

［各実施例及び各比較例の評価］
実施例１〜４及び比較例１，２のリチウムイオン二次電池の各々について、以下の手順で評価試験を行った。この評価試験後、評価指数ＺをＺ＝１００×Ｙ／Ｘ（％）と定義し、各実施例及び各比較例につきこの評価指数Ｚを求めた。その結果を表１に示す。
（評価試験手順）
（１）４．１Ｖまで０．２Ｃで定電流充電を行った後、４．１Ｖ定電圧充電を２時間行った。その後、０．１Ｃで２．５Ｖまで定電流放電を行い、電池の放電容量を測定した。以下の試験では、ここで得られた充放電容量を電池容量とみなした。
（２）ＳＯＣ０％からＳＯＣ５０％まで０．２Ｃで定電流充電を行い、２時間休止した。
（３）２．５Ｖまで２Ｃで定電流放電を行った（この放電容量をＸとした）。
（４）４．１Ｖまで０．２Ｃで定電流充電を行った後、４．１Ｖ定電圧充電を２時間行った（ＳＯＣ１００％）。その後、ＳＯＣ５０％まで０．２Ｃで定電流放電を行い、２時間休止した。
（５）２．５Ｖまで２Ｃで定電流放電を行った（この放電容量をＹとした）。

Figure 0005169341
[Evaluation of Examples and Comparative Examples]
For each of the lithium ion secondary batteries of Examples 1 to 4 and Comparative Examples 1 and 2, an evaluation test was performed according to the following procedure. After this evaluation test, the evaluation index Z was defined as Z = 100 × Y / X (%), and this evaluation index Z was determined for each example and each comparative example. The results are shown in Table 1.
(Evaluation test procedure)
(1) After performing constant current charging at 0.2 C to 4.1 V, 4.1 V constant voltage charging was performed for 2 hours. Then, constant current discharge was performed to 2.5V at 0.1 C, and the discharge capacity of the battery was measured. In the following tests, the charge / discharge capacity obtained here was regarded as the battery capacity.
(2) Constant current charging was performed at 0.2 C from SOC 0% to SOC 50%, and the operation was stopped for 2 hours.
(3) A constant current discharge was performed at 2 C up to 2.5 V (this discharge capacity was X).
(4) After performing constant current charging at 0.2 C up to 4.1 V, 4.1 V constant voltage charging was performed for 2 hours (SOC 100%). Then, constant current discharge was performed at 0.2 C until SOC was 50%, and the operation was stopped for 2 hours.
(5) A constant current discharge was performed at 2 C up to 2.5 V (this discharge capacity was defined as Y).
Figure 0005169341

表１から明らかなように、予備充放電を行わなかった比較例１，２の場合には、評価指数Ｚは９０％未満となり、非特許文献１で報告されているように、Ｘの値がＹの値を大きく上回る結果となった。一方、予備充放電を行った実施例１〜実施例４の場合には、評価指数Ｚは９０％以上となり、Ｘの値とＹの値とが近づき充放電履歴による出力特性の差が低減されることが明らかとなった。こうした効果は、実施例１と実施例２との比較及び実施例３と実施例４との比較から明らかなように、予備充放電の温度が２０℃よりも６０℃の方が高かった。また、実施例１と実施例３との比較及び実施例２と実施例４との比較から明らかなように、電解液にＶＣを添加しなかった場合よりも添加した場合の方が高かった。更に、比較例１と比較例２との比較から明らかなように、予備充放電なしでは、電解液にＶＣを添加しただけでは評価指数Ｚは９０％に達しないこともわかった。   As is clear from Table 1, in the case of Comparative Examples 1 and 2 where no pre-charging / discharging was performed, the evaluation index Z was less than 90%, and as reported in Non-Patent Document 1, the value of X was The result greatly exceeded the value of Y. On the other hand, in the case of Example 1 to Example 4 in which preliminary charge / discharge was performed, the evaluation index Z was 90% or more, and the difference between the output characteristics due to the charge / discharge history was reduced as the value of X approached the value of Y. It became clear. As is clear from the comparison between Example 1 and Example 2 and the comparison between Example 3 and Example 4, these effects were higher when the pre-charge / discharge temperature was 60 ° C than 20 ° C. Further, as apparent from the comparison between Example 1 and Example 3 and the comparison between Example 2 and Example 4, the case where VC was added to the electrolytic solution was higher than the case where VC was not added. Furthermore, as is clear from the comparison between Comparative Example 1 and Comparative Example 2, it was also found that the evaluation index Z does not reach 90% simply by adding VC to the electrolyte without pre-charging and discharging.

ＳＯＣ０％から充電してＳＯＣ５０％に調製したときの正極活物質の模式図である。It is a schematic diagram of the positive electrode active material when it is charged from SOC 0% and adjusted to SOC 50%. ＳＯＣ１００％から放電してＳＯＣ５０％に調製したときの正極活物質の模式図である。It is a schematic diagram of the positive electrode active material when discharged from SOC 100% and adjusted to SOC 50%.

Claims (5)

負極と、オリビン型構造のリチウム複合酸化物を正極活物質とする正極と、前記負極と前記正極との間に介在する非水系電解液とを備えたリチウムイオン二次電池の予備充放電方法であって、
電池組立直後に、充電終止時の正極の電位がリチウム金属に対して３．５〜５．０Ｖ、放電終止時の正極の電位がリチウム金属に対して０〜３．３Ｖとなる充放電を２Ｃレート以上で繰り返し実行する、
リチウムイオン二次電池の予備充放電方法。 A precharge / discharge method for a lithium ion secondary battery comprising: a negative electrode; a positive electrode using a lithium composite oxide having an olivine structure as a positive electrode active material; and a non-aqueous electrolyte solution interposed between the negative electrode and the positive electrode. There,
Immediately after assembly of the battery, 2C is charged and discharged so that the potential of the positive electrode at the end of charging is 3.5 to 5.0 V with respect to lithium metal, and the potential of the positive electrode at the end of discharging is 0 to 3.3 V with respect to lithium metal. Repeat at a rate or higher,
A method for pre-charging and discharging a lithium ion secondary battery. 前記充放電を、充電終止時の正極の電位がリチウム金属に対して３．９〜４．３Ｖ、放電終止時の正極の電位がリチウム金属に対して２．３〜２．７Ｖとなるように実行する、
請求項１に記載のリチウムイオン二次電池の予備充放電方法。 The charging and discharging are performed so that the positive electrode potential at the end of charging is 3.9 to 4.3 V with respect to the lithium metal, and the positive electrode potential at the end of discharging is 2.3 to 2.7 V with respect to the lithium metal. Run,
The preliminary charge / discharge method for a lithium ion secondary battery according to claim 1. 前記充放電を、２０〜６０℃で実行する、
請求項１又は２に記載のリチウムイオン二次電池の予備充放電方法。 The charge / discharge is performed at 20 to 60 ° C.,
The preliminary | backup charge / discharge method of the lithium ion secondary battery of Claim 1 or 2. 前記非水系電解液は、ビニレンカーボネート（ＶＣ）が添加されたカーボネート系溶媒にリチウム支持塩を溶解させた電解液である、
請求項１〜３のいずれか１項に記載のリチウムイオン二次電池の予備充放電方法。 The non-aqueous electrolyte is an electrolyte obtained by dissolving a lithium support salt in a carbonate solvent to which vinylene carbonate (VC) is added.
The preliminary | backup charge / discharge method of the lithium ion secondary battery of any one of Claims 1-3. 負極と、オリビン型構造のリチウム複合酸化物を正極活物質とする正極と、前記負極と前記正極との間に介在する非水系電解液とを備えたリチウムイオン二次電池であって、
ＳＯＣ０％から充電してＳＯＣ５０％に調製したあと電池を放電させたときの放電容量をＸ、ＳＯＣ１００％から放電してＳＯＣ５０％に調製したあと電池を放電させたときの放電容量をＹとしたときの評価指数Ｚ＝１００×Ｙ／Ｘ（％）が９０％以上である、
リチウムイオン二次電池。 A lithium ion secondary battery comprising a negative electrode, a positive electrode having a lithium composite oxide having an olivine structure as a positive electrode active material, and a non-aqueous electrolyte solution interposed between the negative electrode and the positive electrode,
The discharge capacity when the battery is discharged after being charged from SOC 0% and adjusted to SOC 50% is X, and the discharge capacity when the battery is discharged after being discharged from SOC 100% and adjusted to SOC 50% is Y Evaluation index Z = 100 × Y / X (%) is 90% or more,
Lithium ion secondary battery.
JP2008065881A 2008-03-14 2008-03-14 Pre-charge / discharge method for lithium ion secondary battery and lithium ion secondary battery Expired - Fee Related JP5169341B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2008065881A JP5169341B2 (en) 2008-03-14 2008-03-14 Pre-charge / discharge method for lithium ion secondary battery and lithium ion secondary battery

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2008065881A JP5169341B2 (en) 2008-03-14 2008-03-14 Pre-charge / discharge method for lithium ion secondary battery and lithium ion secondary battery

Publications (2)

Publication Number Publication Date
JP2009224119A JP2009224119A (en) 2009-10-01
JP5169341B2 true JP5169341B2 (en) 2013-03-27

Family

ID=41240693

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2008065881A Expired - Fee Related JP5169341B2 (en) 2008-03-14 2008-03-14 Pre-charge / discharge method for lithium ion secondary battery and lithium ion secondary battery

Country Status (1)

Country Link
JP (1) JP5169341B2 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20170194672A1 (en) * 2015-12-30 2017-07-06 Nissan North America, Inc. High current treatment for lithium ion batteries having metal based anodes
JP6765631B2 (en) * 2016-02-29 2020-10-07 住友金属鉱山株式会社 Manufacturing method of positive electrode for non-aqueous electrolyte coin-type battery

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4780361B2 (en) * 2000-10-06 2011-09-28 株式会社豊田中央研究所 Lithium secondary battery
JP4075451B2 (en) * 2001-05-15 2008-04-16 株式会社豊田中央研究所 Lithium secondary battery
JP2004030939A (en) * 2002-06-21 2004-01-29 Matsushita Electric Ind Co Ltd Manufacturing method of lithium secondary battery
JP5017778B2 (en) * 2005-01-05 2012-09-05 株式会社Ｇｓユアサ Positive electrode for non-aqueous electrolyte battery and non-aqueous electrolyte battery
JP5055780B2 (en) * 2006-02-10 2012-10-24 株式会社Ｇｓユアサ Method for producing positive electrode active material and battery using the same
JP5070731B2 (en) * 2006-04-26 2012-11-14 株式会社Ｇｓユアサ Method for producing non-aqueous electrolyte battery
JP2008053220A (en) * 2006-07-25 2008-03-06 Gs Yuasa Corporation:Kk Non-aqueous electrolyte battery and its manufacturing method
WO2009009758A2 (en) * 2007-07-12 2009-01-15 A123 Systems, Inc. Multifunctional mixed metal olivines for lithium ion batteries

Also Published As

Publication number Publication date
JP2009224119A (en) 2009-10-01

Similar Documents

Publication Publication Date Title
KR101753214B1 (en) Cathode additives for lithium secondary battery with high capacity
EP2693556B1 (en) Additive for sodium ion secondary batteries, and sodium ion secondary battery
JP5309927B2 (en) Non-aqueous lithium ion secondary battery
JP2022538962A (en) rechargeable battery cell
KR102525619B1 (en) Rechargeable lithium battery
KR20140148355A (en) Electrolyte Solution for Lithium Secondary Battery and Lithium Secondary Battery Comprising The Same
KR101502832B1 (en) Lithium Battery Having Higher Performance
JP2015018713A (en) Nonaqueous electrolytic solution and lithium-ion secondary battery using the same
KR20150014185A (en) Liquid Electrolyte for Secondary Battery and Lithium Secondary Battery Containing the Same
KR20160081395A (en) An Electrolyte for a lithium ion secondary battery and a lithium ion secondary battery comprising the same
JP2011049114A (en) Lithium-ion secondary battery
KR20170086876A (en) Charging and discharging method for lithium secondary battery
CN103178244B (en) Hybrid energy storage element
KR101906022B1 (en) Process for producing lithium ion secondary battery
JP5593982B2 (en) Non-aqueous electrolyte composition and non-aqueous electrolyte secondary battery
US8980482B2 (en) Nonaqueous electrolyte lithium ion secondary battery
JP5601549B2 (en) Non-aqueous electrolyte and its use
CN104508891A (en) Non-aqueous electrolyte secondary cell
KR101858334B1 (en) Non-aqueous electrolyte secondary battery
JP5169341B2 (en) Pre-charge / discharge method for lithium ion secondary battery and lithium ion secondary battery
CN109643828B (en) Nonaqueous electrolyte storage element
JP2015162304A (en) Nonaqueous electrolyte battery
KR20080029480A (en) Lithium secondary battery, and hybrid capacitor
KR20160081405A (en) An Electrolyte for a lithium ion secondary battery and a lithium ion secondary battery comprising the same
CN105742691A (en) Non-aqueous electrolyte secondary battery and a method for producing the same

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20101207

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20120928

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: 20121204

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20121217

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20160111

Year of fee payment: 3

LAPS Cancellation because of no payment of annual fees