State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University , Hangzhou 310027, China.
Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Province , Hangzhou 310027, China.
ACS Appl Mater Interfaces. 2016 Nov 23;8(46):31653-31660. doi: 10.1021/acsami.6b10716. Epub 2016 Nov 9.
For Li-O batteries, a challenge still remains to achieve high discharge capacity and easy decomposition of the discharge product (LiO) simultaneously. In this work, conformal growth of thin-layered LiO on CoO nanowire arrays (CoO NAs) during discharge is realized through the cocatalytic effect of solid/immobile CoO NAs and mobile Pd nanocrystals (Pd NCs), rendering easy decomposition of LiO during recharge. Meanwhile, high discharge capacity is also ensured with unique array-type design of the catalytic cathode despite the surface growth mode of LiO. The Li-O cells can deliver a high discharge capacity of 5337 mAh g and keep a stable cycling of 258 cycles at a limited capacity of 500 mAh g. The achievement of excellent electrochemical performance is attributed to the highly efficient cocatalytic ability of CoO NAs and Pd NCs as well as the desirable array-type architecture of the catalytic electrode free of carbon and binder. The cocatalytic mechanism of CoO NAs and Pd NCs is clarified by systematic electrochemical tests, microstructural analyses, and ζ-potential measurements.
对于锂氧电池而言，仍然面临着一个挑战，那就是如何同时实现高放电容量和放电产物（LiO）的易于分解。在这项工作中，通过固/不动 CoO 纳米线阵列（CoO NAs）和可动 Pd 纳米晶（Pd NCs）的共催化作用，在放电过程中实现了薄层 LiO 在 CoO 纳米线阵列上的共形生长，从而使得 LiO 在充电过程中易于分解。同时，尽管采用了 LiO 的表面生长模式，具有独特阵列型设计的催化阴极仍能确保高放电容量。Li-O 电池可提供 5337 mAh g 的高放电容量，并在 500 mAh g 的有限容量下保持 258 次稳定循环。优异的电化学性能得益于 CoO NAs 和 Pd NCs 的高效共催化能力以及无碳和无粘结剂的催化电极的理想阵列型结构。通过系统的电化学测试、微观结构分析和 ζ 电位测量，阐明了 CoO NAs 和 Pd NCs 的共催化机制。
