US Patent 7297444 Non-aqueous electrolyte secondary battery

In a non-aqueous electrolyte secondary battery having a negative electrode containing Si as a negative electrode active material, a binder containing a non-crosslinked polyacrylic acid having a weight-average molecular weight of 300,000 to 3,000,000 is incorporated into a negative electrode molded article that constitutes the negative electrode, so as to prevent electrode decay resulting from expansion and contraction during charge/discharge, as well as to achieve high energy density and improved charge/discharge cycle characteristics.