Despite the many potential applications of seawater batteries (SWBs), the limited performance of available materials has hindered their commercialization. To tackle this issue, scientists have developed a novel co-doped carbon material for the anode of SWBs. Their straightforward synthesis route and the high performance of the developed anode material will pave the way for the widespread adoption of SWBs, which are safer and less expensive than lithium-ion batteries.