Two-Dimensional (2D) Covalent Organic Framework as Efficient Cathodes for Binder-free Lithium-Ion Battery.
Two-Dimensional (2D) Covalent Organic Framework as Efficient Cathodes for Binder-free Lithium-Ion Battery.
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DOI：
10.1002/cssc.201903007
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发表时间：
2019-11
期刊：
影响因子：
8.4
通讯作者：
Changjiang Yao;Zhenzhen Wu;Jian Xie;Fei Yu;Wei Guo;Zhichuan J. Xu;Dong‐sheng Li;Shanqing Zhang-Shanqin
中科院分区：
文献类型：
--
作者：
Changjiang Yao;Zhenzhen Wu;Jian Xie;Fei Yu;Wei Guo;Zhichuan J. Xu;Dong‐sheng Li;Shanqing Zhang-Shanqin
寻找新的有机正极材料以解决其在锂离子电池（LIB）中的差的循环稳定性和低容量是非常重要和高度期望的。在这项研究中，一种新的二维（2D）硼氧烷连接的化学活性芘-4，5，9，10-四酮（PTO）共价有机框架，（2D PPTODB COFs）是一种具有优异电化学性能的有机正极材料（4个氧化还原电子）、安全的氧化电位窗口（2.3V-3.08V，Li/Li+）、优异的结构/化学稳定性和强氧化性。通过混合70重量%的PPTODB和30重量%的作为导电添加剂的碳纳米管（CNT）来获得无粘合剂的阴极。由于PPTODB与碳纳米管之间的π-π相互作用以及其快速的电子/离子反应动力学、高的电化学活性等特点，所制备的LIBs具有优异的电化学性能，如198 mAh g-1的高比容量、优异的倍率性能（76%，1000 mA g-1与100 mA g-1），以及稳定的库伦效率（CE，第150次循环时~99.6%）。这项工作表明，无粘合剂的2D电活性材料的概念可能是实现高能量密度储能的一种有前途的策略。
Searching new organic cathode materials to address their poor cycle stability and low capacity in lithium ion batteries (LIBs) is very important and highly desirable. In this research, a novel two-dimensional (2D) boroxine-linked chemically-active pyrene-4,5,9,10-tetraone (PTO) covalent organic framework (2D PPTODB COFs) has been synthesized as an organic cathode material with remarkable electrochemical properties, including high electrochemical activity (4 redox electrons), safe oxidation potential window (between 2.3V and 3.08V, Li/Li+), superb structural/chemical stability, and strong adhesiveness. A binder-free cathode was obtained by the mixing of a 70 wt% PPTODB and 30 wt% carbon nanotubes (CNTs) as a conductive additive. Stemmed from the fast kinetics of electrons/ions, high electrochemical activity, and effective π-π interaction between PPTODB and CNTs, the LIBs with the as-prepared cathode exhibits excellent electrochemical performance such as high specific capacity of 198 mAh g-1, superb rate ability (76 %, 1000 mA g-1 vs. 100 mA g-1), and a stable coulombic efficiency (CE, ~99.6% at 150th cycle). This work suggests that the concept of binder-free 2D electroactive material could be a promising strategy to approach energy storage with high energy density.