NEGATIVE ELECTRODE FOR NON-AQUEOUS ELECTROLYTE SECONDARY BATTERY, AND NON-AQUEOUS ELECTROLYTE SECONDARY BATTERY
An electrode for a non-aqueous electrolyte secondary battery, which is an example of an embodiment, has a belt-shaped negative electrode current collector and a negative electrode mixture layer formed on the surface of the negative electrode current collector. The negative electrode mixture layer contains a first Si-based active material and a second Si-based active material, each of which has a structure in which Si particles are dispersed in an oxide phase. The Si particle content in the first Si-based active material is higher than the Si particle content in the second Si-based active material, and, in the negative electrode mixture layer, the ratio of the mass of the first Si-based active material to the total mass of the first Si-based active material and the second Si-based active material is greater at the center than at the end in the width direction of the negative electrode current collector.
1 . A negative electrode for a non-aqueous electrolyte secondary battery, having:
a band-shaped negative electrode current collector; and
a negative electrode mixture layer formed on a surface of the negative electrode current collector, wherein
the negative electrode mixture layer includes a first Si-based active material and a second Si-based active material,
both the first Si-based active material and the second Si-based active material have a structure in which Si particles are dispersed in an oxide phase, and a content rate of the Si particles in the first Si-based active material is higher than a content rate of the Si particles in the second Si-based active material, and
in the negative electrode mixture layer, a proportion of a mass of the first Si-based active material to a total mass of the first Si-based active material and the second Si-based active material is larger in a central part than in an end part in a width direction of the negative electrode current collector.
2 . The negative electrode for a non-aqueous electrolyte secondary battery according to claim 1 , wherein, before a first charge, the oxide phase contains at least one of lithium silicate and silicon oxide as a main component.
3 . The negative electrode for a non-aqueous electrolyte secondary battery according to claim 2 , wherein, before the first charge,
the oxide phase of the first Si-based active material contains the lithium silicate as a main component, and
the oxide phase of the second Si-based active material contains the silicon oxide as a main component.
4 . A non-aqueous electrolyte secondary battery, comprising:
the negative electrode according to claim 1 ;
a positive electrode; and
a non-aqueous electrolyte.