Lithium secondary-battery pack, electronic device using same, charging system, and charging method

Abstract

A lithium secondary-battery pack of the present invention includes: a lithium secondary battery including an electrode body and a non-aqueous electrolyte, the electrode body including a positive electrode and a negative electrode facing each other, and a separator interposed therebetween; a PTC (Positive Temperature Coefficient) element; and a protection circuit including a field-effect transistor, wherein the negative electrode includes a negative electrode material mixture layer containing a Si-containing material as a negative electrode active material, and, where Z represents an impedance (Ω) of the lithium secondary-battery pack and Q represents a capacity (Ah) of the lithium secondary-battery pack, an impedance capacity index represented by Z/Q is 0.055 Ω/Ah or less.

Dependencies are inferred from the claim text.