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Observation of Electrochemically Driven Elemental Segregation in a Si Alloy Thin‐Film Anode and its Effects on Cyclic Stability for Li‐Ion Batteries |
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| Authors: | Minsub Oh Sekwon Na Chang‐Su Woo Jun‐Ho Jeong Sung‐Soo Kim Alicja Bachmatiuk Mark Hermann Rümmeli Seungmin Hyun Hoo‐Jeong Lee |
| Institution: | 1. School of Advanced Materials Science & Engineering, Sungkyunkwan University, Suwon, South Korea;2. Nano‐Convergence Mechanical Systems Research Division, Korea Institute of Machinery and Materials, Daejeon, South Korea;3. School of Green Energy Technology, Chungnam National University, Daejeon, South Korea;4. Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science, Sungkyunkwan University, Suwon, South Korea;5. Department of Nano Mechatronics, University of Science and Technology, Daejeon, South Korea;6. SKKU Advanced Institute of Nano technology (SAINT), Sungkyunkwan University, Sunwon, South Korea |
| Abstract: | The results of employing (Ti, Fe)‐alloyed Si thin‐film anode for Li‐ion batteries are reported. The material demonstrates an impressive cyclic stability with stable operation for more than 500 cycles at a capacity higher than 1400 mAh g?1. Materials characterization using scanning electron microscopy and transmission electron microscopy illuminates an intriguing materials process behind the performance: ripple‐like pattern formation via electrochemically driven segregation of the inactive elements (Ti and Fe). The ripple structure plays a buffer role by suppressing loss of the active material upon further cycling, allowing the anode to gradually transform into an array of microbumps. The morphological evolution helps the anode endure long cycles (even up to 1000 cycles) without catastrophic failure as the bumps shrank slowly and steadily, consistent with the electrochemical data. |
| Keywords: | anode electrodes cyclic stability lithium‐ion batteries microstructure characterization silicon composites |