Lithium secondary battery and electric device

# imgabs0. The present application discloses a lithium secondary battery and an electrical device. The lithium secondary battery comprises a positive pole piece and a negative pole piece, a positive pole active material layer comprises a positive pole active material Li < 1 + a > M < 1b > Fe < 1-c > AcP < 1-d > EdO4 with the mass ratio not lower than 85 wt%, a negative pole active material layer comprises graphite with the mass ratio not lower than 85 wt%, and the positive pole active material layer located on the single side of the positive pole piece has the surface density CWc with the unit of g/1540.25 mm < 2 > and the reversible lithium capacity Dc with the unit of mAh/1540.25 mm < 2 >; the reversible lithium capacity of the negative electrode active material layer on one side, facing the positive electrode plate, of the negative electrode plate is Da, and the unit is mAh/1540.25 mm < 2 >; the first lithium embedding capacity of the negative electrode active material layer on one side, deviating from the positive electrode plate, of the negative electrode plate is Ca, and the unit is mAh/1540.25 mm < 2 >; the conductivity of the electrolyte in the lithium secondary battery at 25 DEG C is [rho] in S/cm; the lithium secondary battery satisfies the following formula: 1: 1.0337 + 0.37 * CWc-7. 79 * rho < = K1 < = 1.07 + 0.93 * CWc-2. 9 * rho; and/or a formula 2: K2 is greater than or equal to 1.1485 + 0.43 * CWc-9.2 * rho and less than or equal to 1.13 + 1.069 * CWc-1. 7 * rho; wherein (A).