Silicon carbide (SiC) derived from agricultural waste potentially competitive with silicon anodes
Silicon carbide (SiC) derived from agricultural waste potentially competitive with silicon anodes
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源自农业废物的碳化硅 (SiC) 具有与硅阳极竞争的潜力
DOI：
10.1039/d2gc00645f
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发表时间：
2022
期刊：
影响因子：
9.8
通讯作者：
Laine, R. M.
中科院分区：
文献类型：
--
作者：
Yu, M.;Temeche, E.;Indris, S.;Lai, W.;Laine, R. M.
生物质衍生材料为能源储存提供了低碳方法。高比表面积SiC w/wo 13wt%硬碳（SiC/HC，SiC/O），来源于碳热还原二氧化硅贫化的稻壳船体灰（SDRHA），可用作Li+电池阳极。SiC/HC和SiC/O的恒电流循环显示，在600次循环后，容量最终分别增加到>950 mA h g−1（Li1.2-1.4SiC）和>740 mA h g−1（Li1.1SiC）。通过XRD和29 Si MAS NMR进行的尸检调查显示从3C-到6 H-SiC的部分相变，晶胞尺寸没有显著变化。SEM显示循环的电极保持其完整性，这意味着锂化/脱锂时几乎没有体积膨胀，与硅阳极在锂化时>300%的体积变化形成对比。与SiC阳极相比，需要显著的空隙空间来补偿Si的这些体积变化，这表明几乎具有竞争力的容量。6Li MAS NMR和XPS没有显示LixSi的证据，Li更喜欢计算模型支持的全C环境。建模还支持在高Li含量下与3C相的偏离，具有最小的体积变化。
Biomass-derived materials offer low carbon approaches to energy storage. High surface area SiC w/wo 13 wt% hard carbon (SiC/HC, SiC/O), derived from carbothermal reduction of silica depleted rice hull ash (SDRHA), can function as Li+ battery anodes. Galvanostatic cycling of SiC/HC and SiC/O shows capacity increases eventually to >950 mA h g−1 (Li1.2–1.4SiC) and >740 mA h g−1 (Li1.1SiC), respectively, after 600 cycles. Post-mortem investigation via XRD and 29Si MAS NMR reveals partial phase transformation from 3C- to 6H-SiC, with no significant changes in unit cell size. SEMs show cycled electrodes maintain their integrity, implying almost no volume expansion on lithiation/delithiation, contrasting with >300% volume changes in Si anodes on lithiation. Significant void space is needed to compensate for these volume changes with Si in contrast to SiC anodes suggesting nearly competitive capacities. 6Li MAS NMR and XPS show no evidence of LixSi, with Li preferring all-C environments supported by computational modeling. Modeling also supports deviation from the 3C phase at high Li contents with minimal volume changes.