Cyanogel-enabled homogeneous Sb–Ni–C ternary framework electrodes for enhanced sodium storage
Cyanogel-enabled homogeneous Sb–Ni–C ternary framework electrodes for enhanced sodium storage
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氰凝胶均质 Sb-Ni-C 三元框架电极可增强钠存储
DOI：
10.1021/acsnano.7b07985
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发表时间：
--
期刊：
影响因子：
17.1
通讯作者：
Yu Guihua
中科院分区：
文献类型：
--
作者：
Wu Ping;Zhang Anping;Peng Lele;Zhao Fei;Tang Yawen;Zhou Yiming;Yu Guihua
锑（Sb）是先进钠离子电池重要的高容量负极材料，但由于体积膨胀过大导致循环寿命差，阻碍了其实际应用。过渡金属（M = Ni、Cu、Fe等）与碳组分的共掺杂可以协同缓冲Sb组分的体积变化；然而，这些Sb - M - C三元阳极往往受到Sb、M和C组分分布不均匀的影响。在此，我们提出了一种通用的纳米结构凝胶方法来合成均匀的Sb-M-C三元阳极，以充分实现M/C对偶矩阵的协同效应。合成了一种氰基桥接Sb(III) -Ni （II）配位聚合物凝胶（Sb -Ni cyanogel），并将其直接还原为Sb -Ni合金骨架（Sb -Ni骨架）。此外，氧化石墨烯（GO）可以在氰凝胶框架内情境固定化，还原后，还原后的氧化石墨烯（rGO）均匀分布在合金框架内，形成均匀的rGO@Sb -Ni三元框架。具有最佳还原氧化石墨烯含量的rGO@Sb -Ni骨架在1a g-1时具有高可逆容量（~ 468 mA h - 1）和稳定的5 a g-1循环寿命（500次循环后为~ 210 mA h - 1）。提出的氰凝胶使能方法可以扩展到合成其他均相三元框架材料，用于有效的能量存储和电催化。
Antimony (Sb) represents an important high-capacity anode material for advanced sodium ion batteries, but its practical utilization has been primarily hampered by huge volume expansion-induced poor cycling life. The co-incorporation of transition-metal (M = Ni, Cu, Fe,etc.) and carbon components can synergistically buffer the volume change of the Sb component; however, these Sb–M–C ternary anodes often suffer from uneven distribution of Sb, M, and C components. Herein, we propose a general nanostructured gel-enabled methodology to synthesize homogeneous Sb–M–C ternary anodes for fully realizing the synergestic effects from M/C dual matrices. A cyano-bridged Sb(III)–Ni(II) coordination polymer gel (Sb–Ni cyanogel) has been synthesized and directly reduced to an Sb–Ni alloy framework (Sb–Ni framework). Moreover, graphene oxide (GO) can bein situimmobilized within the cyanogel framework, and after reduction, reduced graphene oxide (rGO) is uniformly distributed within the alloy framework, yielding a homogeneous rGO@Sb–Ni ternary framework. The rGO@Sb–Ni framework with optimal rGO content manifests a high reversible capacity of ∼468 mA h g–1at 1 A g–1and stable cycle life at 5 A g–1(∼210 mA h g–1after 500 cycles). The proposed cyanogel-enabled methodology may be extended to synthesize other homogeneous ternary framework materials for efficient energy storage and electrocatalysis.