Panasonic Intellectual Property Management Co., Ltd.

Yuji Oura

Tomoki Shiozaki

Hideharu Takezawa

Takahito Nakayama

Takahiro Takahashi

Daisuke Furusawa

Hajime Nishino

Kazuki Endo

Kazuhiro Yoshii

Yuki Tokuda

Yuta Kuroda

This negative electrode is provided with a negative electrode current collector, and a negative electrode mixture layer formed on the negative electrode current collector, wherein: the negative electrode mixture layer comprises a first layer arranged on the negative electrode current collector, and a second layer arranged on the first layer; the second layer includes graphite particles A having a particle internal porosity of at most 10%: the first layer includes graphite particles B having a particle internal porosity of more than 10%; and the second layer has a water contact angle of at most 50°.

Negative electrode for lithium ion secondary battery, and lithium ion secondary battery

In the present invention, this positive electrode is provided with: a collector; and a composite material layer that is formed on at least one surface of the collector. The composite material layer includes a particulate aggregate formed from inorganic substance particles which do not occlude or emit Li, a conductive material, and a binding material for binding the inorganic particles and the conductive material. According to an exemplary embodiment, the aggregate is present closer to the collector side at least with respect to the thickness-direction center of the composite material layer, and accounts for at least 1.3 vol % with respect to the volume of the composite material layer.

Secondary battery positive electrode and secondary battery

A secondary battery includes: a positive electrode having a positive-electrode current collector and a positive-electrode active-material layer; a negative electrode having a negative-electrode current collector and a negative-electrode active-material layer; a electrolyte; and an insulating tape covering a portion of the positive electrode. Furthermore, the positive-electrode current collector has an exposed section that the positive-electrode active-material layer is not disposed. In addition, at least a portion of the exposed section is covered with the insulating tape; the insulating tape has a substrate material layer and an adhesive layer; and the adhesive layer includes an adhesive agent and an insulating inorganic material.

Secondary battery including insulating tape covering positive electrode

A positive electrode used in a secondary cell that is an example of the present embodiment is provided with a positive electrode collector, an intermediate layer formed on the positive electrode collector, and a positive electrode mixture layer formed on the intermediate layer. The positive electrode mixture layer has a thermally expandable material and a positive electrode active material. The thermally expandable material content of the positive electrode mixture layer is at least 0.1% by mass and less than 5% by mass. The intermediate layer has an insulating inorganic material and a conductive agent. The insulating inorganic material content of the intermediate layer is 80-99% by mass.

Secondary battery

A secondary battery positive electrode is provided with: a positive electrode current collector; a positive electrode mixture layer; and an intermediate layer disposed between the positive electrode current collector and the positive electrode mixture layer. The intermediate layer comprises first particles configured from an electrically conductive material, and second particles which are configured from an insulating inorganic material and have an average grain size greater than an average grain size of the first particles. The volume ratio of the first particles in the intermediate layer is not less than 25% and less than 70%. The volume ratio of the second particles in the intermediate layer is not less than 30% and less than 75%. The density of the intermediate layer is greater than 1 g/cmand not more than 2.5 g/cm.

According to the present invention, a positive electrode is provided with: a positive electrode current collector which contains aluminum; a positive electrode mixture layer which contains a positive electrode active material that is configured of a lithium transition metal oxide; and an intermediate layer which is arranged between the positive electrode current collector and the positive electrode mixture layer. The intermediate layer contains inorganic compound particles, a conductive material and a binder; the circularity is from 5% to 75% (inclusive); the void fraction of the intermediate layer is from 30% to 69% (inclusive); and the average circularity of the inorganic compound particles is from 5% to 75% (inclusive).

A secondary battery includes a positive electrode having a positive electrode current collector and a positive electrode active material layer; a negative electrode having a negative electrode current collector and a negative electrode active material layer; a separator interposed between the electrodes; a electrolyte; a positive electrode lead; and an insulating tape that covers part of the positive electrode. The positive electrode current collector has an exposed portion connected to the positive electrode lead. The positive electrode lead has an extending portion that projects from the exposed portion and an overlapping portion that overlaps the exposed portion. At least part of the exposed portion and at least part of the overlapping portion are covered with the insulating tape. The insulating tape has a substrate layer and an adhesive layer. The substrate layer contains a polyimide. The adhesive layer has an electrical resistance of 1 k&#x3a9;/mmor more at 500&#xb0; C.

A positive electrode is provided with: a positive electrode current collector constituted of aluminum as the main component; a positive electrode mixture layer formed on the positive electrode current collector aid containing a lithium-containing transition metal oxide; and a protective layer interposed between the positive electrode current collector and the positive electrode mixture layer. The protective layer contains inorganic particles, a conductive agent, and a binder material. In the positive electrode, the peel strength between the positive electrode current collector and the protective layer is higher than the peel strength between the protective layer and the positive electrode mixture layer.

Nonaqueous electrolyte secondary battery positive electrode and nonaqueous electrolyte secondary battery

According to the present invention, a positive electrode is provided with: a positive electrode current collector; a positive electrode active material layer which contains a positive electrode active material that is configured from a lithium transition metal oxide; a protective layer which is arranged between the positive electrode current collector and the positive electrode active material layer; and a positive electrode tab which is bonded with the positive electrode current collector at a positive electrode tab bonding part where the positive electrode active material layer and the protective layer are not formed so that the positive electrode current collector is exposed. An end edge of the positive electrode active material layer facing the positive electrode tab and an end edge of the protective layer facing the positive electrode tab are arranged in different positions in the longitudinal direction of the positive electrode.

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Osaka, Japan

Yuji Oura