Nissan Motor Company Limited

Envision Aesc Japan Ltd.

Miyuki Terado

Shinji Yamamoto

Masahiro Yamamoto

Kenichi Ochiai

The present invention relates to a secondary battery in which a stacked electrode assembly having a cathode, an anode and a separator is accommodated together with an electrolytic solution between exterior members. In the present invention, the secondary battery has a plurality of joint parts at which the outer peripheral portion of the separator is joined with the exterior members and a holding part formed at least between the joint parts so as to hold therein the electrolytic solution, wherein a sum of perimeters of the joint parts is longer than a perimeter of a rectangle of minimum area enclosing therein all of the joint parts. In this configuration, it is possible to refill the stacked electrode assembly with the electrolytic solution and protect the joint parts from breakage while preventing displacement of the stacked electrode assembly in the secondary battery.

Secondary battery

A non-aqueous electrolyte secondary battery of the invention has a power generating element with a single-cell layer which comprises a positive electrode including a positive electrode active material layer formed on a surface of a positive electrode collector, a negative electrode including a negative electrode active material layer formed on a surface of a negative electrode collector and a separator disposed between the positive electrode the negative electrode and containing a non-aqueous electrolyte, in which a value RA (=Rzjis (2)/Rzjis(1)) for the ratio between the surface roughness (Rzjis(1)) of the surface of the negative electrode active material layer on the side in contact with the separator and the surface roughness (Rzjis(2)) of the surface of the separator on the side in contact with the negative electrode active material layer is 0.15 to 0.85.

Non-aqueous electrolyte secondary battery

A gas diffusion electrode material of the present invention includes: a porous body () formed of continuous and discontinuous polytetrafluoroethylene microfibers () and having three-dimensionally continuous micropores (); and a conductive material () supported on the porous body (). Moreover, a density of the polytetrafluoroethylene microfiber () is lower in a surface region (A) of a cross section of the porous body () than in an intermediate region (B) of the cross section. In accordance with the present invention, the polytetrafluoroethylene having the predetermined three-dimensional structure is used, and so on. Therefore, it is possible to provide a gas diffusion electrode material excellent in power generation characteristics and durability.

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Yokohama, Japan

Miyuki Terado