High-Performance Sn-TiC/C-CNTs Composite Anode for KIBs—Stress Mitigation and Electrochemical Performance Enhancement

As the global demand for lithium-ion batteries (LIBs) continues to rise, potassium-ion batteries (KIBs) have emerged as a promising alternative due to the abundance and low cost of potassium. However, the development of efficient KIB anode materials faces significant challenges, particularly in managing large volume changes and stress propagation during cycling.<br/>This study investigates the potential of Sn-TiC/C-CNTs composite anodes to address these issues, focusing on the mitigation of stress propagation and improvement of electrochemical performance. Using high-energy ball milling, Sn particles were combined with a TiC/C-CNTs matrix to form a robust composite with enhanced mechanical and electrical properties. The inclusion of carbon nanotubes (CNTs) and titanium carbide (TiC) in the matrix improves electrical conductivity and mitigates microcrack formation, resulting in better cycling stability and capacity retention compared to pure Sn anodes.<br/>The Sn-TiC/C-CNTs composite exhibited a reversible capacity of 315.89 mAh g^-1 after 50 cycles, showing significant improvement over Sn and Sn-TiC/C anodes. Detailed electrochemical tests, including cyclic voltammetry and impedance spectroscopy, confirmed the superior performance of the Sn-TiC/C-CNTs anode, highlighting its potential for high-performance KIBs.<br/>Theoretical modeling and phase analysis further elucidated the underlying mechanisms of stress relaxation and volume expansion management within the composite anode. This study demonstrates that the integration of Sn with TiC/C-CNTs matrix provides a promising strategy for enhancing the stability and performance of alloy-type anodes in KIBs, paving the way for the development of more reliable and efficient potassium-ion batteries.<br/>1. K. Huang, Z. Xing, L. Wang, X. Wu, W. Zhao, X. Qi, H. Wang, Z. Ju, Z. Ju, <i>J. Mater. Chem. A </i><b>2018</b>, <i>6</i>, 434.<br/>2. I. Sultana, T. Ramireddy, M. M. Rahman, Y. Chen, A. M. Glushenkov, <i>Chem. Commun. </i><b>2016</b>, <i>52</i>, 9279.<br/>3. H. Kim, J. C. Kim, M. Bianchini, D.-H. Seo, J. Rodriguez-Garcia, G. Ceder, <i>Adv. Energy Mater. </i><b>2017</b>, <i>8</i>, 1702384.<br/>4. K. Chihara, A. Katogi, K. Kubota, S. Komaba, <i>Chem. Commun. </i><b>2017</b>, <i>53</i>, 5208.<br/>5. J.-Y. Hwang, S.-T. Myung, Y.-K. Sun, <i>Adv. Funct. Mater. </i><b>2018</b>, <i>28</i>, 1802938.<br/>6. C. Li, A. T. Bi, H. L. Chen, Y. R. Pei, M. Zhao, C. C. Yang, Q. Jiang, <i>J. Mater. Chem. A </i><b>2021</b>, <i>9</i>, 5740.<br/>7. Y.-S. Fang, T. H. Do, K.-A. Chiu, W.-C. Chen, L.i Chang, <i>Coatings </i><b>2020</b>, <i>10</i>, 647.