abstract |
A negative-electrode active material includes a mixed power of a first active-material powder composed of a granular graphite particle, and a second active-material powder composed of a plate-shaped graphite particle having a thickness of from 0.3 nm to 100 nm and a major-axis-direction length of from 0.1 μm to 500 μm. Since the plate-shaped graphite particle has a lam liar structure, the plate-shaped graphite particle excels in the strength and flexibility, and function as a negative-electrode active material because lithium ions come in and out between the layers. Therefore, while securing the flexibility of negative-electrode active-material layer, the contradictory event between the capacity and the conductive property is solved. |