en.wikipedia.org/wiki/Electrolysis_of_water

An aqueous electrolyte can considerably raise conductivity. The electrolyte disassociates into cations and anions; the anions rush towards the anode and neutralize the buildup of positively charged H+ there; similarly, the cations rush towards the cathode and neutralize the buildup of negatively charged OH– there. This allows the continuous flow of electricity.

化学一般是实验发现现象结果再去找理论解释的。。 这个理论解释不清楚就打补丁，再找一个解释。
因为例外太多了...
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FROM 123.120.162.*