Nonaqueous electrolyte secondary battery and process for producing negative electrode thereof

Abstract

A process for producing a negative electrode, comprising the first step of forming multiple columnar active substance agglomerates capable of electrochemical occlusion / release of lithium ions on a surface of current collector and the second step of incorporating granular lithium in interstices of the active substance agglomerates.

Description

technical field [0001] The present invention relates to a nonaqueous electrolyte secondary battery, and more specifically, to improving the capacity of a nonaqueous electrolyte secondary battery using an active material having a high capacity density, such as silicon (Si) or a Si compound, for a negative electrode. Background technique [0002] Non-aqueous electrolyte secondary batteries typified by lithium ion secondary batteries have attracted attention as high-capacity power sources in equipment mainly portable equipment. In recent years, in order to further increase the capacity of such batteries, development of electrode materials (effective use of high-capacity-density active materials and reduction of sub-materials) and improvement of structural components (thinning, etc.) have been actively carried out. [0003] Among them, Si and Si compounds, which are negative electrode active materials, are high-capacity-density materials whose theoretical capacity is much higher...

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Problems solved by technology

On the other hand, when a binder is used, the binder remains on the surface of the negative electrode, which causes an increase in internal resistance

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