Negative electrode for lithium ion secondary battery and lithium ion secondary battery comprising the same

A lithium ion secondary battery, comprising:

• a negative electrode;
• a positive electrode;
• and
• an electrolyte solution, wherein the negative electrode comprises:
• (i) a negative electrode mixture layer comprising a negative electrode active material and a negative electrode binder;
• and
• (ii) a negative electrode current collector,
• the negative electrode active material comprises an alloy comprising silicon (Si alloy),
• the Si alloy is crystalline and has a median diameter (D50 particle size) of 0.1 μm or more and 1.2 μm or less,
• an amount of the negative electrode binder based on the weight of the negative electrode mixture layer is 12% by weight or more and 50% by weight or less,
• the negative electrode binder comprises a polyacrylic acid, and
• the electrolyte solution comprises 4-fluoro-1,3-dioxolan-2-one (FEC).