Soft generators hold great promise both in powering flexible electronics and in signaling specific parameter variations. In particular, mechanical motions for electricity harvest have attracted great interests due to their ubiquity and relevance to human activities. Instead of the widely reported piezoelectric and triboelectric generators, in this study an efficient electric-double-layer (EDL) generator is designed by embedding liquid metal (LM) into biologic porous ionogels. When pulsating LM into or out of the ionogel pores, an alternating current would be produced from the variation of EDL area between LM and ionogels. The porous ionogels are produced unprecedentedly by partially fusing biologic nanofibrils and ionic liquid, whose porosities and adhesion to LM surfaces are tuned elaborately to ensure their reversible compressibility, freely moving of LM within the internal channels and hereby maximal variation of EDL area for optimal energy harvest, e.g., showing an alternating current with amplitude up to 25 µA cm−2 and energy power of 4 mW cm−2 higher than many piezoelectric and triboelectric generators. Besides electricity harvest from motions, this soft generator can also serve as a self-powered and highly sensitive tactile sensor.