Abstract High performance is indispensable for amorphous carbon materials toward sodium-ion batteries anode. Heteroatom doping has proved to be an effective strategy to improve the electrochemical performance of carbon-based materials. In this paper, N, P dual-doped carbon sheets (N, P CS) from the rinds of corn stalks have been successfully synthesized via a hydrothermal reaction using the cheap (NH4)2HPO4 as nitrogen and phosphorus source. SEM and TEM images showed that the N, P CS was composed of loose and stacked graphitic carbon sheets, which facilitated the penetration of electrolyte and ion diffusion. Higher ID/IG value (1.692) implied more defective sites on the surface of graphitic sheet to be generated after N and P co-doping, which combined with larger graphene layer distance (0.391 nm) contributed to the high performance of the N, P CS. When used as anode for sodium ion batteries, it presents a specific capacity of 277 mAh g−1 after 100 cycles at 0.25C, and a specific capacity of 202 mAh g−1 after 200 cycles at 1C. Even at a high rate of 5C, a stable specific capacity of 105 mAh g−1 still could be delivered after 2000 cycles, suggesting an excellent cycle stability and superior rate capability.

中文翻译：

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从玉米秸秆到 N, P-Dual 掺杂碳片再到高性能钠离子电池阳极的可持续途径

摘要 无定形碳材料对于钠离子电池负极来说，高性能是必不可少的。杂原子掺杂已被证明是提高碳基材料电化学性能的有效策略。在本文中，利用廉价的 (NH4)2HPO4 作为氮和磷源，通过水热反应成功地合成了来自玉米秸秆皮的 N, P 双掺杂碳片 (N, P CS)。SEM 和 TEM 图像表明，N、PC CS 由松散和堆叠的石墨碳片组成，有利于电解质的渗透和离子扩散。较高的 ID/IG 值 (1.692) 意味着在 N 和 P 共掺杂后将在石墨片表面上产生更多的缺陷位点，这与较大的石墨烯层距 (0.391 nm) 相结合有助于 N、P 的高性能CS。当用作钠离子电池的阳极时，它在0.25C下循环100次后比容量为277 mAh g-1，在1C下循环200次后比容量为202 mAh g-1。即使在 5C 的高倍率下，2000 次循环后仍可提供 105 mAh g-1 的稳定比容量，表明其具有优异的循环稳定性和优异的倍率性能。