Semiconductor Energy Laboratory Co., Ltd.

Rie Yokoi

Jun Ishikawa

Kyosuke Ito

Toru Itakura

Mayumi Mikami

Yumiko Saito

Teppei Oguni

Aya Uchida

A mixture of amorphous PAHs and at least one of a carrier ion storage metal, a Sn compound, a carrier ion storage alloy, a metal compound, Si, Sb, and SiOis used as the negative electrode active material. The theoretical capacity of amorphous PAHs greatly exceeds that of a graphite based carbon material. Thus, the use of amorphous PAHs enables the negative electrode active material to have a higher capacity than in the case of using the graphite-based carbon material. Further, addition of at least one of the carrier ion storage metal, the Sn compound, the carrier ion storage alloy, the metal compound, Si, Sb, and SiOto the amorphous PAHs enables the negative electrode active material to have a higher capacity than the case of only using the amorphous PAHs.

Negative electrode of power storage device and power storage device

A nonaqueous electrolyte of the present invention includes an ionic liquid including a first alicyclic quaternary ammonium cation having one or more substituents, a second alicyclic quaternary ammonium cation having an alicyclic skeleton that is the same as an alicyclic skeleton of the first alicyclic quaternary ammonium cation, and a counter anion to the first alicyclic quaternary ammonium cation and the second alicyclic quaternary ammonium cation and an alkali metal salt. In the second alicyclic quaternary ammonium cation, one of substituents bonded to a nitrogen atom in the alicyclic skeleton is a substituent including a halogen element. In the ionic liquid, the amount of a salt including the second alicyclic quaternary ammonium cation is less than or equal to 1 wt % per unit weight of the ionic liquid, or is less than or equal to 0.8 wt % per unit weight of the nonaqueous electrolyte.

Ionic liquid, nonaqueous electrolyte, and power storage device

A mixture of amorphous PAHs and at least one of a carrier ion storage metal, a Sn compound, a carrier ion storage alloy, a metal compound, Si, Sb, and SiOis used as the negative electrode active material. The theoretical capacity of amorphous PAHs greatly exceeds that of a graphite-based carbon material. Thus, the use of amorphous PAHs enables the negative electrode active material to have a higher capacity than in the case of using the graphite-based carbon material. Further, addition of at least one of the carrier ion storage metal, the Sn compound, the carrier ion storage alloy, the metal compound, Si, Sb, and SiOto the amorphous PAHs enables the negative electrode active material to have a higher capacity than the case of only using the amorphous PAHs.

A power storage device with high capacity, a power storage device with high energy density, a highly reliable power storage device, and a long-life power storage device are provided. The power storage device includes a positive electrode, a separator, a negative electrode, and an electrolytic solution. The electrolytic solution contains an alkali metal salt and an ionic liquid. The separator is located between the positive electrode and the negative electrode. At least part of the positive electrode overlaps with the negative electrode. At least part of an end portion of the negative electrode is located inside a region between end portions of the positive electrode.

Power storage device and electronic device

A power storage device with reduced initial irreversible capacity is provided. The power storage device includes a positive electrode including a positive electrode current collector and a positive electrode active material layer, a negative electrode including a negative electrode current collector and a negative electrode active material layer, and an electrolyte solution. In the negative electrode active material layer, the content percentage of a carbon material with an R value of 1.1 or more is less than 2 wt %. The R value refers to a ratio of a peak intensity Ito a peak intensity I(I/I). The peak intensity Iand the peak intensity Iare observed by Raman spectrometry at a Raman shift of 1360 cmand a Raman shift of 1580 cm, respectively. The electrolyte solution contains a lithium ion and an ionic liquid composed of an organic cation and an anion.

Power storage device

To provide an ionic liquid which has at least one of properties such as high ionic conductivity, a small reduction in ionic conductivity at a low temperature, a low melting point, and a low viscosity. To provide a power storage device having higher initial charge and discharge efficiency than a power storage device containing a conventional ionic liquid. A cyclic quaternary ammonium salt is liquid at room temperature and contains a quaternary spiro ammonium cation having an asymmetrical structure including two aliphatic rings and one or more substituents bonded to one or both of the two aliphatic rings and an anion corresponding to the quaternary spiro ammonium cation. The power storage device includes a positive electrode, a negative electrode, and a nonaqueous electrolyte containing the cyclic quaternary ammonium salt as a nonaqueous solvent.

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Kanagawa, Japan

Rie Yokoi