Extended Data Fig. 4: Chronopotentiometry measurements at different current densities in NaBr electrolyte without a buffer.

Electrolyte composition: 1.5 M NaBr with 3.8 mM Na2Cr2O7. The electrolyte was heated to 60 °C and stirred at a rate of 400 rpm. The current densities are indicated by the labels in the figures (in units of mA/cm2). The voltage is presented without IR correction.