Transition metal chalcogenides have received considerable attention in sodium-ion batteries. However, their practical application is greatly hindered by the low conductivity and sluggish kinetics. Here, we report a hierarchical structure, featuring carbon nanosheets grafted on carbon nanofibers, as a substrate that supports cobalt diselenide (CoSe₂@ carbon nanosheets [CNS]/carbon nanofiber [CNF]) to boost the conductivity and prevent electrode pulverization. Moreover, we demonstrate that manganese doping can be used to expand the sodium-ion diffusion channels in Co_1-xMn_xSe₂ and induce the synergistic lattice expansion of carbon nanosheets, alleviating the sluggish kinetics. Exploiting this strategy, the Co_1-xMn_xSe₂@CNS/CNF with pre-sodium treatment can deliver a high specific energy density of 409.4 Wh kg⁻¹ at 0.1 C when paired with Na₂V_1.85Fe_0.15(PO₄)₃/C cathode in a full cell. This work may provide insights into how doping induces hierarchical lattice expansion of transition metal chalcogenide/carbon hybrids to alleviate sluggish kinetics and enhance sodium storage.

过渡金属硫族化物已在钠离子电池中引起了相当大的关注。但是，其低电导率和缓慢的动力学极大地阻碍了它们的实际应用。在这里，我们报告了一种分层结构，其特征是接枝在碳纳米纤维上的碳纳米片作为支持二硒化钴的基材（CoSe ₂ @碳纳米片[CNS] /碳纳米纤维[CNF]）以提高导电性并防止电极粉化。此外，我们证明锰掺杂可用于扩展Co _1-x Mn _x Se _2中的钠离子扩散通道，并诱导碳纳米片的协同晶格扩展，从而缓解了缓慢的动力学。利用这种策略，Co _1-x与全电池中的Na ₂ V _1.85 Fe _0.15（PO ₄）₃ / C阴极配对时，经过预钠处理的Mn _x Se ₂ @ CNS / CNF在0.1 C时可提供409.4 Wh kg ^-1的高比能量密度。。这项工作可能会提供有关掺杂如何诱导过渡金属硫族化物/碳杂化物的分层晶格扩展以减轻缓慢反应动力学和增强钠存储的见解。