Power storage device

摘要

A power storage device in which silicon is used as a negative electrode active material layer and which can have an improved performance such as higher discharge capacity, and a method for manufacturing the power storage device are provided. A power storage device includes a current collector and a silicon layer having a function as an active material layer over the current collector. The silicon layer includes a thin film portion in contact with the current collector, a plurality of bases, and a plurality of whisker-like protrusions extending from the plurality of bases. A protrusion extending from one of the plurality of bases is partly combined with a protrusion extending from another one of the plurality of bases.

主权项

1. A power storage device comprising:
a current collector; and a silicon layer having a function as an active material layer over the current collector, wherein the silicon layer comprises:
a thin silicon film portion in contact with the current collector,a first base comprising crystalline silicon formed in the thin silicon film portion and having a stump-like shape;a second base comprising crystalline silicon formed in the thin silicon film portion and having a stump-like shape;a first whisker-like protrusion extending from the first base, the first whisker-like protrusion comprising a first core and a first shell;a second whisker-like protrusion extending from the first base, the second whisker-like protrusion comprising a second core and a second shell;a third whisker-like protrusion extending from the second base, the third whisker-like protrusion comprising third core and third shell; anda fourth whisker-like protrusion extending from the second base, the fourth whisker-like protrusion comprising a fourth core and a fourth shell, wherein each of the first core and the third core comprises crystalline silicon, wherein each of the first shell and the third shell comprises amorphous silicon, and wherein the first shell is directly combined with the third shell.