An Yongling, Pei Zhihao, Luan Deyan, Lou Xiong Wen David
Department of Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon 999077, Hong Kong, China.
Sci Adv. 2025 May 9;11(19):eadv2007. doi: 10.1126/sciadv.adv2007.
Anode-free sodium batteries (AFNBs) are regarded as promising alternatives for next-generation energy storage systems because of their high energy density, high safety, cost-effectiveness, and simple manufacturing processes. However, their practical application is limited by a low coulombic efficiency (CE) and a short lifespan resulting from a large volume change and the growth of Na dendrites. Here, we propose a three-dimensional versatile host composed of interconnected N,P-codoped carbon macroporous fibers incorporated with CoP nanoparticles (denoted as CoP@N/P-CMFs) for selective nucleation and uniform deposition of Na. The porous skeleton reduces structural stress and inhibits dendrite growth by decreasing local current density and homogenizing Na flux. Furthermore, the sodiophilic CoP and N,P-codoped carbon reduce the energy barrier for Na nucleation, further manipulating homogeneous Na growth. Consequently, the CoP@N/P-CMFs exhibit an ultrahigh CE of more than 99.97% (10 milliamperes per square centimeter and 10 milliampere-hours per square centimeter) and dendrite-free Na deposition. When coupled with a NaV(PO) cathode, the assembled foldable AFNBs demonstrate stable cycling performance.
无阳极钠电池（AFNBs）因其高能量密度、高安全性、成本效益和简单的制造工艺，被视为下一代储能系统的有前途的替代方案。然而，它们的实际应用受到低库仑效率（CE）和短寿命的限制，这是由于体积变化大和钠枝晶生长所致。在此，我们提出一种三维多功能主体，由相互连接的氮、磷共掺杂碳大孔纤维与磷化钴纳米颗粒结合而成（表示为CoP@N/P-CMFs），用于钠的选择性成核和均匀沉积。多孔骨架通过降低局部电流密度和使钠通量均匀化来降低结构应力并抑制枝晶生长。此外，亲钠的CoP和氮、磷共掺杂碳降低了钠成核的能垒，进一步控制了钠的均匀生长。因此，CoP@N/P-CMFs表现出超过99.97%的超高库仑效率（每平方厘米10毫安和每平方厘米10毫安时）以及无枝晶的钠沉积。当与NaV(PO) 阴极耦合时，组装的可折叠无阳极钠电池表现出稳定的循环性能。
