The electrolysis of bicarbonate solutions offers a direct route for converting alkaline CO2 capture solutions into value-added products. Alkaline CO2 capture exploits the reaction of CO2 with OH- to form aqueous HCO3-, which can be converted back into CO2 in-situ ( i-CO2) by protons sourced from a bipolar membrane (BPM). Bicarbonate electrolysis is currently too energy intensive to be economically viable, with the largest energy input coming from the voltage drop across the membrane. BPMs are usually thicker than monopolar membranes, causing high Ohmic losses and limited water transport to the water dissociation junction. This causes the membrane to dry out and require excessively high voltages to operate at high current densities. To date, little research has been directed towards designing BPMs for bicarbonate electrolysis. Our work focuses on designing BPMs with low voltage drops while keeping the amount of i-CO2 suppliedto the cathode high. In this study, we present custom-made BPMs that enable bicarbonate electrolysis at a current density of 100 mA cm-2 and a cell voltage < 3 V, with cell voltage remaining < 10 V at current densities in excess of 1 A cm-2. We also demonstrate a correlation between a thicker cation exchange layer and higher i-CO2 generation and elucidate the cause of this phenomenon.