NEGATIVE ELECTRODE PLATE, SECONDARY BATTERY, AND DEVICE THEREOF

This application relates to a negative electrode plate, a secondary battery and apparatus thereof. The secondary battery of the present application comprises a negative electrode plate (30), the negative electrode plate (30) comprises a composite current collector (10) and a negative electrode active material layer (20) disposed on at least one surface of the composite current collector (10), the negative electrode active material layer (20) comprises a silicon-based active material, the silicon-based active material accounts for 0.5 wt% to 50 wt% of total mass of the negative electrode active material layer (20), and the composite current collector (10) comprises a polymer support layer (101) and a metal conductive layer (102) disposed on at least one surface of the polymer support layer (101), and the composite current collector (10) has a brittleness parameter C ranging from 0.03 to 0.5. The secondary battery and the negative electrode plate (30) of the present application achieve good coordination between the current collector (10) and the negative electrode active material layer (20), which improves the pulverization and exfoliation problem of the silicon-based negative electrode plate (30) during charging and discharging, thereby obtaining relatively high weight energy density and meanwhile improving cycle life of the secondary battery.