Positive electrode for nonaqueous electrolyte secondary battery and nonaqueous electrolyte secondary battery using the same

Abstract

To provide a positive electrode for a nonaqueous electrolyte secondary battery having excellent flexibility and capable of increasing the reliability and productivity, and a nonaqueous electrolyte secondary battery using the positive electrode. The positive electrode for a nonaqueous electrolyte secondary battery includes an active material layer that contains: a positive-electrode active material; a binder made of a fluorine-contained resin containing a vinylidene fluoride unit; and an electrolyte represented by one of the following general formulae (1) and (2): wherein M represents a metal element, R1 and R2 each represent fluorine or a fluorinated alkyl group having one to three carbon atoms and are identical to or different from each other, and n represents an integer of 1 to 3; wherein M represents a metal element, R3 represents a fluorinated alkylene group having two to four carbon atoms, and n represents an integer of 1 to 3.

Description

technical field [0001] The present invention relates to a positive electrode for a nonaqueous electrolyte secondary battery using a fluororesin containing a vinylidene fluoride unit as a binder, a method for producing the same, and a nonaqueous electrolyte secondary battery using the positive electrode. Background technique [0002] In recent years, the miniaturization and weight reduction of mobile information terminals such as mobile phones, notebook computers, and personal digital assistants (PDAs) have rapidly progressed, and higher capacity batteries are required as their driving power sources. As a secondary battery that meets this requirement, an alloy that can store and release lithium ions, or a lithium-ion secondary battery that uses a carbon material or the like as a negative electrode active material and a lithium-transition metal composite oxide as a positive electrode active The density of the battery has attracted much attention. [0003] The positive electro...

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Problems solved by technology

[0003] The positive electrode active material of the current lithium ion secondary battery mainly uses lithium cobalt oxide (LiCoO 2 ), but there are the following problems: cobalt is relatively expensive; in addition, when the charging termination potential is 4.3V (vs.Li / Li + ) in the case of lithium cobalt oxide can only use about 160mAh / g, the capacity is low

However, in these prior arts, there is no disclosure of adding a lithium salt to the active material layer of the positive electrode, nor does it disclose any improvement in the flexibility of the positive electrode thereby.

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