Taiyo Yuden Co., Ltd.

Koji Kano

Katsunori Yokoshima

Takatoshi Nagase

Shinji Ishii

Hiroki Takahashi

Takeo Tsuzuki

Yuki Kawai

Tomoya Iwazaki

An electrochemical device includes a first electrode unit; a second electrode unit; a third electrode unit; a first lithium ion supply source, which is disposed between the first electrode unit and the third electrode unit and includes a first current collector that is a porous metal foil having a first main surface on the side of the first electrode unit; a second lithium ion supply source, which is disposed between the second electrode unit and the third electrode unit and includes a second current collector that is a porous metal foil having a third main surface on the side of the second electrode unit; and an electrolyte. Lithium ions are pre-doped from first metal lithium attached to the first main surface, and second metal lithium attached to the third main surface, into the negative electrode of each electrode unit.

Electrochemical device

In an electric storage element, a negative electrode has a negative-electrode collector and a negative-electrode active material layer provided on a principal face of the negative-electrode collector, the positive electrode having a positive-electrode collector and a positive-electrode active material layer provided on a principal face of the positive-electrode collector, and the separator insulating the negative electrode and the positive electrode, are stacked and wound together. A negative-electrode terminal and a positive-electrode terminal are electrically connected to the negative-electrode collector and the positive-electrode collector, respectively, and projects from a winding structure along a direction of a center axis of winding. A first protective tape covers the negative-electrode terminal and has lower ion permeability than that of the separator. The positive electrode has, in a part facing the first protective tape via the separator, a first region for inhibiting release of lithium ions therefrom.

Electric storage element

An electrochemical device has a positive electrode, a negative electrode, separators, and an electrolyte. The negative electrode has a first and second negative-electrode active-material layers and a negative-electrode collector which has (i) a first principal face on which the first negative-electrode active-material layer is formed, and (ii) a second principal face having a coated area where the second negative-electrode active-material layer is formed, and an uncoated area where no second negative-electrode active-material layer is formed. The negative-electrode collector has multiple through holes that interconnect the first and second principal faces wherein the boundary of the coated area and the uncoated area intersects the opening of at least one of the multiple through holes. The electrochemical device is such that a metallic lithium is electrically connected to the uncoated area and immersed in the electrolyte, to allow for pre-doping of the negative-electrode active-material layers with lithium ions.

In an embodiment, an electrochemical device includes a winding structure which has a negative electrode, a positive electrode, and separators stacked and wound together; a negative-electrode terminal; a positive-electrode terminal; a first protective tape which covers the negative-electrode terminal and a negative-electrode active material layer; a second protective tape which covers the positive-electrode terminal and a positive-electrode active material layer; and electrolyte, wherein the positive-electrode terminal is separated from the negative-electrode terminal by a first distance. The width corresponding to the sum of a first width of the first protective tape along a winding direction of the winding structure, and a second width of the second protective tape along the winding direction, is smaller than a value obtained by multiplying the first distance by pi.

An electrochemical device is constituted by a positive electrode, a negative electrode, and separators that are wound in such a way that the first principal face of the negative electrode and third principal face of the positive electrode are on the inner side of winding, while the second principal face of the negative electrode and fourth principal face of the positive electrode are on the outer side of winding, with the separators separating the positive electrode and negative electrode; wherein the second principal face has a first region opposed to the positive electrode via the separator and a second region on the outermost side of winding and not opposed to the positive electrode, the second region includes a first uncoated region where no negative electrode active material layer is formed, and a metal lithium is joined to the first uncoated region and immersed in electrolytic solution.

Electrochemical device and method of manufacturing electrochemical device

An electrochemical device includes: a positive electrode having a positive-electrode collector made of conductive material, and a positive-electrode active material layer formed on the positive-electrode collector; a negative electrode having a negative-electrode collector made of conductive material, and a negative-electrode active material layer formed on the negative-electrode collector; separators placed between the positive electrode and the negative electrode; and an electrolyte immersing the positive electrode, negative electrode, and separators. Metallic lithium is joined to a lithium-electrode collector, and the lithium-electrode collector is placed in a manner contacting the negative-electrode active material layer, and immersed in the electrolyte, so that the negative-electrode active material is pre-doped with lithium ions. The electrochemical device can offer high capacitance and excellent productivity.

An electrochemical device has a positive electrode, a negative electrode, separators, and an electrolyte. The negative electrode has: a negative-electrode collector having a first principal face and a second principal face on the opposite side of the first principal face; a first negative-electrode active-material layer formed on the first principal face; and a second negative-electrode active-material layer which is formed intermittently on the second principal face and whose density of negative-electrode active material is lower than that of the first negative-electrode active-material layer. In the electrolyte, the positive electrode, negative electrode, and separators are immersed. The electrochemical device is such that the first and second negative-electrode active-material layers are pre-doped with lithium ions as a metallic lithium is electrically connected to the second principal face where the second negative-electrode active-material layer is not formed, and then immersed in the electrolyte.

An electrochemical device includes a positive electrode, a negative electrode, and separators which are stacked and wound together, and electrolytic solution. A negative-electrode terminal is provided which is made of metal, and has a joining part which is a part joined to the principal face of the negative-electrode collector. The negative electrode has a first width, the positive electrode has a second width, which is smaller than the first width, and the separators have a third width, which is greater than the first width, along the direction parallel with the center axis of winding. The length of the joining part along the direction parallel with the center axis of winding is equal to or greater than the second width, but equal to or smaller than the third width.

In an embodiment, an electric storage deviceincludes: an electric storage elementhaving a positive electrode and a negative electrode; a non-aqueous electrolytic solution constituted by a non-aqueous solvent primarily containing cyclic ester and cyclic carbonate ester, in which an electrolyte containing lithium salt is dissolved and to which a sulfonate ester derivative whose reduction potential is higher than that of the cyclic ester and cyclic carbonate ester is added; and an outer containerthat stores the electric storage elementand non-aqueous electrolytic solution. The electric storage device can offer both good low-temperature characteristics and good high-temperature reliability.

Electric storage device

An object of the present invention is to provide a way to reduce the internal resistance of a lithium ion capacitor without causing its capacity or withstand voltage to drop. The present invention provides a lithium ion capacitor having a positive electrode, a negative electrode, a separator, and an electrolyte solution, wherein the separator contains cellulose that has been given a treatment to create carbon-carbon double bonds.

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Takasaki, Japan

Koji Kano