Electrochemical Lithium Alloying Behavior of Guest-Free Type II Silicon Clathrates
Electrochemical Lithium Alloying Behavior of Guest-Free Type II Silicon Clathrates
复制标题
无客体 II 型硅包合物的电化学锂合金化行为
DOI：
10.1021/acs.jpcc.1c04020
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Chan, Candace K.
中科院分区：
文献类型：
--
作者：
Dopilka, Andrew;Childs, Amanda;Bobev, Svilen;Chan, Candace K.
无客体的II型Si笼形物（Si 136）是Si的开放骨架多晶型物，其显示与Li的独特电化学反应。锂离子首先拓扑插入到空笼形物笼中，然后通过合金化反应形成无定形硅化锂相。合金化反应电压高于在其他Si电极中看到的那些，这表明在形成的非晶相中存在结构差异。采用同步辐射X射线全散射测量和对分布函数分析来表征锂化后形成的非晶相。结果表明，与金刚石立方Si相比，笼形物在锂化的早期就完全非晶化，形成了Si-Si键合量相对较大的相。Li最初插入笼形物笼中建立了重要的Li扩散路径，其在动力学上能够形成具有比通常在其他硅基电极中看到的更低Li含量的非晶相。在初始的晶体到非晶转化反应之后，锂化通过固溶合金化发生。这些结果证明了Li到合金化主体中的拓扑插入如何能够在动力学上实现改性的反应途径，从而导致整个电极中更均匀的锂化，这对于Li离子电池应用是有益的。
The guest-free type II Si clathrate (Si136) is an open framework polymorph of Si that displays unique electrochemical reactions with Li. Li ions are first topotactically inserted into the vacant clathrate cages, followed by an alloying reaction that forms an amorphous lithium silicide phase. The alloying reaction voltage is higher than those seen in other Si electrodes, suggesting that there are structural differences in the formed amorphous phases. Synchrotron X-ray total scattering measurements and pair distribution function analysis are employed to characterize the amorphous phases formed after lithiation. The results show that the clathrate becomes completely amorphous at an earlier stage of lithiation when compared to diamond cubic Si, forming a phase with comparatively larger amounts of Si–Si bonding. The initial insertion of Li into the clathrate cages establishes important Li diffusion paths that kinetically enable the formation of an amorphous phase with lower Li content than typically seen in other silicon-based electrodes. After the initial crystalline-to-amorphous conversion reaction, lithiation takes place via solid-solution alloying. These results demonstrate how the topotactic insertion of Li into an alloying host can kinetically enable modified reaction pathways leading to more homogeneous lithiation throughout the electrode, which is beneficial for Li-ion battery applications.
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影响因子：
3.7
作者：
Dopilka, Andrew;Peng, Xihong;Chan, Candace K.
通讯作者：
Chan, Candace K.
硅笼形物-II的电化学锂化
影响因子：
3.9
作者：
T. Langer;Sven Dupke;H. Trill;S. Passerini;H. Eckert;R. Pöttgen;M. Winter
通讯作者：
M. Winter
影响因子：
15.1
作者：
Li, Ying;Raghavan, Rahul;Wagner, Nicholas A.;Davidowski, Stephen K.;Baggetto, Loic;Zhao, Ran;Cheng, Qian;Yarger, Jeffery L.;Veith, Gabriel M.;Ellis-Terrell, Carol;Miller, Michael A.;Chan, Kwai S.;Chan, Candace K.
通讯作者：
Chan, Candace K.
DOI：
10.1002/aesr.202000114
发表时间：
2021-05-01
期刊：
ADVANCED ENERGY AND SUSTAINABILITY RESEARCH
影响因子：
--
作者：
Dopilka, Andrew;Weller, J. Mark;Chan, Candace K.
通讯作者：
Chan, Candace K.
影响因子：
3.7
作者：
Uxa, Daniel;Jerliu, Bujar;Schmidt, Harald
通讯作者：
Schmidt, Harald