Development of high volumetric capacitance, high rate performance and low-cost electrode materials for supercapacitors is still a significant challenge. Among the various promising candidates, carbon nanofibers (CNFs) with heteroatom functionalization have attracted increasing attention. Herein, a type of nonporous CNFs combined with a heteroatom functionalization strategy is proposed for high performance supercapacitor electrodes. Tri-heteroatom functionalization of nonporous carbon nanofibers was carried out by tetraethyl orthosilicate (TEOS) and phosphorus (H₃PO₄) activation of polyacrylonitrile (PAN) through electrospinning and subsequent thermal treatment. The optimal electrode material showed a high gravimetric capacitance of 243.7 F g⁻¹ at 0.5 A g⁻¹, superior rate capability with ∼83% retention at rates ranging from 0.5 A g⁻¹ to 30 A g⁻¹ and excellent cycle stability (capacitance retention rate >100% after 8000 cycles at a high current density of 30 A g⁻¹). It is worth noting that the nonporous CNF also possesses a high packing density, which presents a maximum volumetric capacitance of 253.4 F cm⁻³ at 0.5 A g⁻¹ and 209 F cm⁻³ at 30 A g⁻¹. The current synthetic strategy of preparing nonporous carbon architectures with multi-heteroatom doping offers an eco-friendly, feasible, and cost-effective way for constructing high-performance electrode materials employed in supercapacitors.

中文翻译：

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具有高体积电容的生态友好型无孔碳纳米纤维：通过氮，磷和硅的三掺杂提高了速率性能†

用于超级电容器的高体积电容，高倍率性能和低成本电极材料的开发仍然是一项重大挑战。在各种有前途的候选物中，具有杂原子功能化的碳纳米纤维（CNF）引起了越来越多的关注。在此，针对高性能超级电容器电极，提出了一种结合杂原子功能化策略的无孔CNF。无纺布碳纳米纤维的三杂原子官能化是通过电纺丝和随后的热处理，通过原硅酸四乙酯（TEOS）和聚丙烯腈（PAN）的磷（H ₃ PO ₄）活化来进行的。最佳电极材料在0.5 A g时显示出243.7 F g ^-1的高重力电容^-1，优异的倍率性能与~83％的保留在速率范围从0.5 A克^-1至30 A G ^-1和优异的循环稳定性（电容保持率> 100％后的30 A g的高电流密度8000次^{- 1}）。值得注意的是，无孔CNF也具有高堆积密度，在0.5 A g ^-1时呈现最大体积电容为253.4 F cm ^-3，在30 A g ^-1时呈现最大209 F cm ^-3。当前使用多杂原子掺杂制备无孔碳结构的合成策略为构建超级电容器中使用的高性能电极材料提供了一种生态友好，可行且经济高效的方法。