Tdk Corporation

Kenji Nishizawa

Katsuo Naoi

Mitsuo Kougo

Kiyonori Hinoki

Masahiro Saegusa

Kazutoshi Emoto

Hidetake Itoh

Yoshihiko Ohashi

Keita Kobayashi

A fiber-containing polymer film contains a host polymer and fibrous substances. The fiber-containing polymer film has an orientation area where the fibrous substances are oriented in a direction substantially parallel to a main surface of the fiber-containing polymer film and in substantially the same direction.

Fiber-containing polymer film and method of manufacturing same, and electrochemical device and method of manufacturing same

An electrode manufacturing method which can lower the impedance of electrochemical devices is provided. The electrode manufacturing method comprises the steps of applying a coating material containing an active material particle, a binder, and a good solvent for the binder to a current collector, so as to form a coating film made of the coating material; removing the good solvent from the coating film; applying a poor solvent for the binder to the coating film having removed the good solvent; and pressing the coating film coated with the poor solvent.

Electrode manufacturing method

A lithium-ion secondary battery separator has a porous structure formed by laminating a second polymer layer, a first polymer layer, and a second polymer layer in sequence. The second polymer layer has a melting point lower than that of the first polymer layer. The second polymer layer has a higher molecular part formed on a side in contact with the first polymer layer and a lower molecular part formed on a side farther from the first polymer layer than is the higher molecular part. The higher and lower molecular parts have a weight-average molecular weight ratio (higher molecular part/lower molecular part) of 4 to 19 therebetween.

Lithium-ion secondary battery separator and lithium-ion secondary battery

An electrochemical device comprises an electrode matrix including a multilayer structure composed of a positive electrode, a negative electrode, and a first separator, and first and second dummy electrodes electrically connected to the positive and negative electrodes, respectively. The first and second dummy electrodes have respective opposing parts opposing each other through a second separator at an outer peripheral part of the electrode matrix. One or each of the first and second dummy electrodes has a resistance control layer at least on a side where the opposing parts oppose each other. The resistance control layer has such a resistance value that an estimated internal short circuit current between the first and second dummy electrodes is equivalent to 0.09 C to 1.00 C. The first and second dummy electrodes are adapted to short-circuit each other at a lower temperature than the positive and negative electrodes do.

Electrochemical device

An electrode having a current collector with a plurality of through holes, and active material layers provided on both sides of the current collector. The current collector has projections extending on the top side or on the back side of the current collector from edges of the through holes, and an angle between each of the projections and a surface direction of the current collector is in the range of 30 to 80&#xb0;.

Electrode

An electrochemical device having an electrode matrix including a multilayer structure laminating positive and negative electrodes with a separator interposed therebetween; wherein at least one of the positive and negative electrodes has a resistance control layer at least at an edge part exposed when the separator thermally shrinks on a surface on the separator side; and wherein the resistance control layer has a resistance value as a total resistance value of the electrode matrix falling in such a range that an estimated internal short circuit current between the positive and negative electrodes is equivalent to 0.09 C to 1 C.

An electrochemical device has an armor; a structure housed in the armor and having a separator disposed between first and second electrodes; and external terminals with respective leads connected to the first and second electrodes of the structure, respectively, and extending from the interior of the armor across a sealed portion of the armor to the outside; at least a surface of an intersection in each of the leads crossing the sealed portion is provided with at least one of depressed portion and projected portion. This electrochemical device is realized in compact size and with high reliability.

Growing community of inventors

Tokyo, Japan

Kenji Nishizawa