Impact of Surface Modification on the Lithium, Sodium, and Potassium Intercalation Efficiency and Capacity of Few-Layer Graphene Electrodes
Impact of Surface Modification on the Lithium, Sodium, and Potassium Intercalation Efficiency and Capacity of Few-Layer Graphene Electrodes
复制标题
表面改性对少层石墨烯电极锂、钠、钾嵌入效率和容量的影响
DOI：
10.1021/acsami.9b23105
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发表时间：
2020
影响因子：
9.5
通讯作者：
Mendoza-Cortes, Jose L.
中科院分区：
文献类型：
--
作者：
Nijamudheen, A.;Sarbapalli, Dipobrato;Hui, Jingshu;Rodríguez-López, Joaquín;Mendoza-Cortes, Jose L.
在传统的锂离子电池（LIB）中，石墨形成负极或阳极。虽然Na被认为是Li的最有吸引力的替代物之一，但在环境条件下在石墨材料内实现可逆的Na嵌入仍然是一个挑战。更高效的碳质阳极材料是开发先进的锂离子电池和超越锂离子电池技术所需要的。我们假设具有不同表面电子性质的二维材料为离子插入到少层石墨烯（FLG）阳极中创造了条件。这是因为电极/电解质界面的改变潜在地改变了FLG的薄块体中离子嵌入的能量学和机制。通过第一性原理计算，我们表明，FLG阳极的电子，结构和热力学性质可以通过在FLG电极的最上层的共价杂原子取代，或通过将FLG与单面氟化石墨烯或Janus型氢氟石墨烯单层连接来微调。当与2D表面改性剂适当地接合时，FLG表现出有利的热力学用于Li+、Na+和K+嵌入。值得注意的是，Na在碳层内的可逆结合在热力学上是允许的，并且对于Na插层改性的FLG阳极可以实现大的存储容量。电荷转移促进的改性FLG的电子可调谐性的起源是合理的各种理论方法。
In a conventional lithium-ion battery (LIB), graphite forms the negative electrode or anode. Although Na is considered one of the most attractive alternatives to Li, achieving reversible Na intercalation within graphitic materials under ambient conditions remains a challenge. More efficient carbonaceous anode materials are desired for developing advanced LIBs andbeyond Li-ionbattery technologies. We hypothesized that two-dimensional materials with distinct surface electronic properties create conditions for ion insertion into few-layer graphene (FLG) anodes. This is because modification of the electrode/electrolyte interface potentially modifies the energetics and mechanisms of ion intercalation in the thin bulk of FLG. Through first-principles calculations; we show that the electronic, structural, and thermodynamic properties of FLG anodes can be fine-tuned by a covalent heteroatom substitution at the uppermost layer of the FLG electrode, or by interfacing FLG with a single-side fluorinated graphene or a Janus-type hydrofluorographene monolayer. When suitably interfaced with the 2D surface modifier, FLG exhibits favorable thermodynamics for the Li+, Na+, and K+intercalation. Remarkably, the reversible binding of Na within carbon layers becomes thermodynamically allowed, and a large storage capacity can be achieved for the Na intercalated modified FLG anodes. The origin of charge-transfer promoted electronic tunability of modified FLGs is rationalized by various theoretical methods.