Hard carbon (HC) is considered the most promising anode material for sodium ion batteries (SIBs), but still faces urgent challenges such as poor rate capability and low initial Coulombic efficiency (ICE). To improve these issues, herein, we creatively combine membrane science with electrode technology, using phase inversion methods to produce a carbon membrane with a 3D “overpass” hierarchical porous carbon structure as the free-standing anode for SIBs. Such an efficient and controllable strategy forms a channel-skeleton coupling structure in the carbon membrane that promotes electron/ion transport, improves the wettability of electrolytes, and boosts the Na storage performance comprehensively. In particular, the optimal sample (PMP-5) shows a superior rate capability of 257.6 mAh g^-1 at 5 C and excellent cycling stability (91% retention rate after 300 cycles at 0.5 C). Meanwhile, since without any binder, the free-standing carbon membrane electrode shows an astonishing ICE of 90.5%. More importantly, when matched with a layered O3-Na(NiFeMn)_1/3O₂ cathode, the full-cell shows a high energy density of 287 Wh kg^-1, excellent rate capability and cycling stability. Our work provides a feasible strategy to boost the Na storage capability of HC anodes by membrane science and pore engineering and serves as a theory guide for designing other superb electrode materials.

硬碳（HC）被认为是钠离子电池（SIB）最有前途的负极材料，但仍面临着倍率能力差和初始库仑效率（ICE）低等紧迫挑战。为了改善这些问题，我们创造性地将膜科学与电极技术相结合，使用相转化方法生产具有 3D“立交桥”分级多孔碳结构的碳膜作为 SIB 的独立阳极。这种高效可控的策略在碳膜中形成了通道-骨架耦合结构，促进了电子/离子传输，提高了电解质的润湿性，全面提升了钠的储存性能。特别是，最佳样品（PMP-5）显示出257.6 mAh g ^{-1的优异倍率能力}在 5 C 和出色的循环稳定性（在 0.5 C 下 300 次循环后保留率为 91%）。同时，由于没有任何粘合剂，独立式碳膜电极显示出惊人的 90.5% 的 ICE。更重要的是，当与层状O3-Na(NiFeMn) _1/3 O ₂正极匹配时，全电池具有287 Wh kg ^-1的高能量密度、优异的倍率性能和循环稳定性。我们的工作为通过膜科学和孔工程提高 HC 阳极的钠存储能力提供了可行的策略，并为设计其他优秀电极材料提供了理论指导。