Negative electrode for power storage device, power storage, device and electrical device
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorsKiyofumi Ogino, Yumiko Yoneda, Rika Yatabe, Nobuhiro Inoue
Life of this patent
Estimating the term…
Abstract
A power storage device having high capacitance is provided. A power storage device with excellent cycle characteristics is provided. A power storage device with high charge and discharge efficiency is provided. A power storage device including a negative electrode with low resistance is provided. A negative electrode for the power storage device includes a current collector and an active material layer including a plurality of active material particles over the current collector. The active material particle is silicon, and the size of the silicon particle is greater than or equal to 0.001 μm and less than or equal to 7 μm.
Claims8
A method for manufacturing an electrode, comprising steps of:
- grinding a silicon wafer to obtain silicon particles;
- mixing the silicon particles, graphene oxide, a precursor of polyimide and a first solvent to obtain a slurry;
- forming an electrode by applying the slurry to a current collector and removing the first solvent in the slurry;
- and
- performing a heat treatment to the electrode at a temperature higher than or equal to 200° C. and lower than or equal to 400° C.,
- wherein the silicon wafer comprises phosphorus or boron as an impurity so as to change a resistivity into a range of 10−4 Ω·cm to 12 Ω·cm,
- wherein a D90 value of the silicon particles is less than or equal to 3.305 μm,
- wherein an average particle size of the silicon particles are greater than or equal to 0.1 μm and less than or equal to 0.842 μm, and
- wherein the graphene oxide is reduced and the precursor of polyimide makes polyimide in the step of performing the heat treatment.
Dependencies are inferred from the claim text.