| The Anode Electrodes for Potassium-Ion Batteries Zelang Jian1; 1WUHAN UNIVERSITY OF TECHNOLOGY, Wuhan, China; PAPER: 441/Battery/Invited (Oral) SCHEDULED: 11:45/Sat. 26 Oct. 2019/Coralino ABSTRACT: The poor lithium resources and high cost limited the application of lithium-ion batteries in energy storage. Due to the low cost and similar electrochemical performance with lithium-ion batteries, potassium ion batteries are the promising candidates for energy storage. We, for the first time, reported electrochemical potassium insertion in graphite in a nonaqueous electrolyte, which can exhibit a high reversible capacity of 273 mAh/g. Ex-situ XRD studies confirm that KC36, KC24, and KC8 sequentially form upon potassiation, whereas depotassiation recovers graphite through phase transformations in an opposite sequence. Graphite shows moderate rate capability and relatively fast capacity fading. To improve the performance of carbon K-ion anodes, we designed two low-density nongraphitic carbon: soft carbon and hard carbon. Those low-density carbons have large graphene layer, which has lots of benefits for high-performance potassium ion batteries. Firstly, the large graphene layer can accommodate large volume change, leading good cycling performance; secondly, K+ can fast extract/insert out/into the graphene layer. Therefore, both soft and hard carbons exhibit cyclability and rate capability much superior to that of graphite. Our work opened up a new paradigm toward rechargeable K-ion batteries. To get high capacity, carbon-coated Bi nanocomposite was designed as well. It exhibits a high capacity and extremely high rate ability. These works push forward the development of rechargeable K-ion battery References: 1. Z. Jian, W. Luo and X. Ji, J. Am. Chem. Soc., 2015, 137, 11566 2. Z. Jian, Z. Xing, C. Bommier, Z. Li and X. Ji, Adv. Energy Mater., 2016, 6, 1501874. 3. Z. Jian, S. Hwang, Z. Li, A. S. Hernandez, X. Wang, Z. Xing, D. Su and X. Ji* Adv. Funct. Mater., 2017, 27, 1700324; |
