Biomass-derived carbon is a promising electrode material in energy storage devices. However, how to improve its low capacity and stability, and slow diffusion kinetics during lithium storage remains a challenge. In this research, we propose a “self-assembly-template” method to prepare B, N codoped porous carbon (BN-C) with a nanosandwich structure and abundant pyridinic N-B species. The nanosandwich structure can increase powder density and cycle stability by constructing a stable solid electrolyte interphase film, shortening the Li⁺ diffusion pathway, and accommodating volume expansion during repeated charging/discharging. The abundant pyridinic N-B species can simultaneously promote the adsorption/desorption of Li⁺/PF₆⁻ and reduce the diffusion barrier. The BN-C electrode showed a high lithium-ion storage capacity of above 1140 mAh g⁻¹ at 0.05 A g⁻¹ and superior stability (96.5% retained after 2000 cycles). Moreover, owing to the synergistic effect of the nanosandwich structure and pyridinic N-B species, the assembled symmetrical BN-C//BN-C full cell shows a high energy density of 234.7 W h kg⁻¹, high power density of 39.38 kW kg⁻¹, and excellent cycling stability, superior to most of the other cells reported in the literature. As the density functional theory simulation demonstrated, pyridinic N-B shows enhanced adsorption activity for Li⁺ and PF₆⁻, which promotes an increase in the capacity of the anode and cathode, respectively. Meanwhile, the relatively lower diffusion barrier of pyridinic N-B promotes Li⁺ migration, resulting in good rate performance. Therefore, this study provides a new approach for the synergistic modulation of a nanostructure and an active site simultaneously to fabricate the carbon electrode material in energy storage devices.

中文翻译：

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木质素衍生碳，具有吡啶 NB 掺杂和纳米三明治结构，可实现高稳定的锂存储

生物质衍生的碳是一种很有前景的储能设备电极材料。然而，如何改善其低容量和稳定性以及锂存储过程中缓慢的扩散动力学仍然是一个挑战。在本研究中，我们提出了一种“自组装模板”方法来制备具有纳米三明治结构和丰富的吡啶NB物种的B、N共掺杂多孔碳（BN-C）。纳米三明治结构可以通过构建稳定的固体电解质界面膜、缩短Li ⁺扩散路径并适应重复充电/放电过程中的体积膨胀来提高粉末密度和循环稳定性。丰富的吡啶NB物种可以同时促进Li ⁺ /PF ₆ ^-的吸附/解吸并降低扩散势垒。 BN-C电极在0.05 A g ^{-1时表现出高于1140 mAh g -1}的高锂离子存储容量和优异的稳定性（2000次循环后保留96.5%）。此外，由于纳米三明治结构和吡啶NB物种的协同效应，组装的对称BN-C//BN-C全电池表现出234.7 W h kg ^-1的高能量密度，39.38 kW kg - 的高功率密度^{。 1}，以及优异的循环稳定性，优于文献报道的大多数其他电池。密度泛函理论模拟表明，吡啶NB对Li ⁺和PF ₆ ^-的吸附活性增强，分别促进阳极和阴极容量的增加。同时，吡啶NB相对较低的扩散势垒促进了Li ⁺迁移，从而产生良好的倍率性能。因此，这项研究提供了一种同时协同调节纳米结构和活性位点来制造储能装置中碳电极材料的新方法。