Silica depleted rice hull ash (SDRHA), an agricultural waste, as a high-performance hybrid lithium-ion capacitor
Silica depleted rice hull ash (SDRHA), an agricultural waste, as a high-performance hybrid lithium-ion capacitor
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DOI：
10.1039/d0gc01746a
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发表时间：
2020-07
期刊：
影响因子：
9.8
通讯作者：
Eleni Temeche;Mengjie Yu;R. Laine
中科院分区：
文献类型：
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作者：
Eleni Temeche;Mengjie Yu;R. Laine
在稻壳燃烧发电期间产生的稻壳船体灰（RHA，农业废物）由高表面积SiO2（80-90重量%）和10-20重量%碳（总共80 m2 g-1）组成（在稀酸浸提之后）。RHA SiO2很容易通过蒸馏（螺硅氧烷）提取，产生SDRHA，这为开发“绿色”混合锂离子电容器（LIC）电极提供了机会。SDRHA由50- 65wt%的SiO2和剩余的碳组成，比表面积为220 m2 g-1。SDRHA微结构呈现出高度不规则和无序的纳米复合材料，其由通过石墨烯层紧密连接的纳米二氧化硅组成，增强了充电/放电过程中的锂离子迁移率。通过组装Li/SDRHA半电池和LiNi0.6Co0.2Mn0.2O2（NMC 622）-SDRHA全电池来评估SDRHA电化学性质。半电池在0.5C下提供250 mA h g−1的高比容量，并在2C下保持200 mA h g−1的容量400 h。与高C倍率下基于NMC的电池的差循环性能相比，混合全电池在4C下表现出200 F g−1的高比电容。此外，半混合电池和全混合电池都表现出优异的库仑效率（100%）。这些结果表明，低成本和环境友好的SDRHA，可以作为一个潜在的替代电极材料的LICs。
Rice hull ash (RHA, an agricultural waste) produced during combustion of rice hulls to generate electricity consists (following dilute acid leaching) of high surface area SiO2 (80–90 wt%) and 10–20 wt% carbon (80 m2 g−1 total). RHA SiO2 is easily extracted by distillation (spirosiloxane) producing SDRHA, which offers an opportunity to develop “green” hybrid lithium-ion capacitors (LICs) electrodes. SDRHA consists of 50–65 wt% SiO2 with the remainder carbon with a specific surface area of ≈220 m2 g−1. SDRHA microstructure presents a highly irregular and disordered nanocomposite composed of nanosilica closely connected via graphene layers enhancing Li-ion mobility during charge/discharge process. SDRHA electrochemical properties were assessed by assembling Li/SDRHA half-cells and LiNi0.6Co0.2Mn0.2O2 (NMC622)-SDRHA full-cells. The half-cell delivered a high specific capacity of 250 mA h g−1 at 0.5C and retained a capacity of 200 mA h g−1 at 2C for 400 h. In contrast to the poor cycle performance of NMC based batteries at high C-rates, the hybrid full-cell demonstrated a high specific capacitance of 200 F g−1 at 4C. In addition, both the half and full hybrid cells demonstrate excellent coulombic efficiencies (∼100%). These results suggest that low cost and environmentally friendly SDRHA, may serve as a potential alternative electrode material for LICs.