Space‐Confined Guest Synthesis to Fabricate Sn‐Monodispersed N‐Doped Mesoporous Host toward Anode‐Free Na Batteries

for over 1000 cycles with capacity retention of 92.1%). Furthermore, high-energy/power-density anode-less and anode-free Na cells are achieved. This work presents an effective heteroatom-doping approach for fabricating multifunctional porous carbon materials and developing high-performance metal batteries.