  In this paper, building upon the discovery of asymmetric rectified electric
fields (AREF) in recent experiments [S.H. Hashemi et al., Physical Review
Letters 121, 185504 (2018)], we explore the generation of AREF by applying a
sawtooth-like voltage to 1:1 electrolytes with equal diffusion coefficients
confined between two planar blocking electrodes. This differs from an earlier
approach based on a sinusoidal AC voltage applied to 1:1 electrolytes with
unequal diffusion coefficients. By numerically solving the full
Poisson-Nernst-Planck equations, we demonstrate that AREF can be generated by a
slow rise and a fast drop of the potential (or vice versa), even for
electrolytes with equal diffusion coefficients of the cations and anions. We
employ an analytically constructed equivalent electric circuit to explain the
underlying physical mechanism. Importantly, we find that the strength of AREF
can be effectively tuned from zero to its maximal value by only manipulating
the time-dependence of the driving voltage, eliminating the necessity to modify
the electrolyte composition between experiments. This provides valuable
insights to control the manipulation of AREF, which facilitates enhanced
applications in diverse electrochemical systems.
