Electrochemical energy storage in batteries is crucial for successfully transitioning from fossil fuel usage to a sustainable energy economy . Lithium-ion batteries (LIBs) exhibit a high energy density and operating voltage while maintaining a sufficiently long cycle life. Thus, LIBs have established themselves as the prime non-stationary energy storage solution . However, LIBs cannot store the inexorably increasing energy needed for today's society for various reasons. Not the least of these reasons is the relative scarcity of lithium in the earth's crust and its uneven global distribution, combined with the environmentally unfriendly mining process. It is, therefore, essential to diversify energy storage beyond lithium. One of the most promising alternatives to lithium batteries are sodium batteries which, unlike lithium, do not suffer from scarcity issues due to sodium's relative abundance.