We report the generation of an 8.5-nJ chirped pulse from a mode-locked all-fiber Yb-doped laser. Mode- locking is achieved through nonlinear polarization evolution (NPE) along with spectral filtering. The laser delivers 135 mW of average output power with positively chirped 10.9-ps pulses. The pulse repetition rate is 15.9 MHz, which results in an energy of 8.5 nJ per pulse. The externally dechirped pulse duration is 223 fs, and the pulse energy is 6 nJ, which corresponds to the peak power of~27 kW.