Mobile ion-enabled phenomena make β-Zn₄Sb₃ a promising material in terms of the re-entry phase instability behavior, mixed electronic ionic conduction, and thermoelectric performance. This work utilizes fast Zn²⁺ migration under a sawtooth waveform electric field and a dynamical growth of a 3-dimensional ionic conduction network to achieve ultra-fast synthesis of β-Zn₄Sb₃. The interplay between mobile ions, electric field, and temperature field creates core-shell crystalline-amorphous microstructures that self-adaptively stabilize β-Zn₄Sb₃. Cd or Ge doping on the Zn site further stabilizes β-Zn₄Sb₃ by restricting long-range Zn²⁺ migration and extends the high thermoelectric performance temperature range. These findings provide insight into developing mixed-conduction thermoelectric materials, batteries, and other functional materials.
