fig2

Figure 2. Mechanism of the BPE iontronic memristor. (A) Schematic diagram of ion behavior and potential illustration under opposite bias in Al system; (B) Schematic diagram of ion behavior under opposite bias in ACNT system; (C) Schematic diagram of ion behavior and potential illustration under opposite bias in ACNT/Al system. E_ox,1 and E_red,1 respectively represent the critical potentials of half-reactions at the anodic pole and cathodic pole in Al. E’_ox,1 and E’_red,1 respectively represent the critical potentials of half-reactions at the anodic pole and cathodic pole in ACNT/Al. ΔE₁ and ΔE’₁ represent the net driving potential in Al and ACNT/Al, respectively. The parameters with the subscript “2” correspond to the respective values under the reversed bias. BPE: Bipolar electrode; Al: aluminum; ACNT: a carbon nanotube array; ACNT/Al: Al and CNT array-based aluminum; CNT: carbon nanotube.