INITIAL CHARGING METHOD FOR LITHIUM ION SECONDARY BATTERY AND MANUFACTURING METHOD

• Main Authors: SHIMURA YOSUKE, MATSUYAMA YOSHIO, SUMI TOMOHIDE
• Format: Patent
• Language: English; Japanese
• Published: 09.03.2017
• Subjects: BASIC ELECTRIC ELEMENTS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTINGELECTRIC POWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY; SYSTEMS FOR STORING ELECTRIC ENERGY

PROBLEM TO BE SOLVED: To provide an initial charging method for a lithium ion secondary battery that can shorten an initial charging time in an initial charging operation for a battery irrespective of provision of a coating preferable to negative active material particles, etc., and a battery manufacturing method using the same.SOLUTION: An initial charging method for a battery having a positive electrode 21, a negative electrode 31, and nonaqueous electrolytic solution 40. The battery 1 has a characteristic that a value E of a second-order differential (dQ/dVc) of a charged charge amount Q by a battery voltage Vc transits from a positive value to a value below zero in the course of initial charging in connection with formation of coating films 25, 35 on negative electrode active material particles 34, etc. by only a firsts predetermined frequency Ns. The initial charging method comprises a first charging step S53 for charging the battery 1 with a first charging current I1 of 0.5C or less, and a second charging step S5B for charging the battery 1 with a second charging current I2 larger than the first charging current l1 until a charging end voltage Ve when the second-order differential value E transit from the positive value to a value of zero or less by the first predetermined frequency Ns.SELECTED DRAWING: Figure 6 【課題】電池の初充電において、負極活物質粒子等に良好な被膜を設けながらも、初充電時間を短くできるリチウムイオン二次電池の初充電方法、及びこれを用いた電池の製造方法を提供する。【解決手段】正極21と負極31と非水電解液40とを備える電池1の初充電方法である。電池1は初充電の途中で、第１所定回数Nsだけ、負極活物質粒子34等への被膜25,35形成に伴い、充電した電荷量Ｑの電池電圧Ｖｃによる二階微分（ｄ2Ｑ／ｄＶｃ2）の値Eが、正の値からゼロ以下の値に遷移する特性を有している。本初充電方法は、電池1を０．５Ｃ以下の第１充電電流I1で充電する第１充電工程S53と、第１所定回数Ns、二階微分値Eが正の値からゼロ以下の値に遷移した場合に、電池1を第１充電電流I1よりも大きい第２充電電流I2で、充電終止電圧Veまで充電を行う第２充電工程S5Bと、を備える。【選択図】図６