The present invention relates to a liquid electrolyte for a secondary battery, and a secondary battery and a secondary battery system, comprising same. The liquid electrolyte for a secondary battery according to the present invention comprises: a solvent; an electrolyte salt; and anisotropic magnetic particles. The anisotropic magnetic particles contained in the liquid electrolyte are dispersed in the liquid medium of the liquid electrolyte, and through the application of an external magnetic field, rotation of the anisotropic magnetic particles can be generated and micro-convection and a dynamic state of the internal electrolyte can be induced. Accordingly, the formation of metal dendrites can be suppressed.
