Phthalocyanine-based covalent organic frameworks as novel anode materials for high-performance lithium-ion/sodium-ion batteries

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 425; p. 131630
• Main Authors: Zhao, Jianjun, Zhou, Miaomiao, Chen, Jun, Tao, Lihong, Zhang, Qian, Li, Zhifeng, Zhong, Shengwen, Fu, Haikuo, Wang, Hua, Wu, Lijue
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2021
• Subjects: Covalent organic frameworks; Energy storage; Lithium/Sodium ion batteries; Organic electrode; Phthalocyanine; Covalent organic frameworks; Phthalocyanine; Lithium/Sodium ion batteries; Organic electrode; Energy storage
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2021.131630

Phthalocyanine-based covalent organic frameworks (NA-NiPc, PPDA-NiPc and DAB-NiPc) with different pore sizes are synthesized by a catalyst-free coupling reaction, which inhibits dissolution in the electrolyte and provides large specific surface area and open mesoporous channels for Li+. As the pore size of the frame increases, the surface area of the material increases accordingly, resulting in improved electrochemical behaviors. The NA-NiPc, PPDA-NiPc and DAB-NiPc electrodes display high capacity, long cycling stability, and excellent rate capability both in LIBs and NIBs. [Display omitted] •Pc-based frameworks with different pore sizes of 1.55, 2.11 and 2.74 nm are synthesized.•No solubility in electrolyte and large specific surface areas are observed.•The surface area increases with the pore size, resulting in improved electrochemical behaviors.•Excellent capacity, cycle stability, and rate capability both in LIBs and NIBs are observed. In this work, three kinds of phthalocyanine-based covalent organic frameworks, NA-NiPc (4-nitronickel phthalocyanine + 4-aminonickel phthalocyanine), PPDA-NiPc (4-nitronickel phthalocyanine + p-phenylenediamine) and DAB-NiPc (4-nitronickel phthalocyanine + 4,4′-diaminobiphenyl), with different pore sizes are synthesized by a catalyst-free coupling reaction. The X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) and Transmission electron microscopy (TEM) test results indicate that the pore sizes of the NA-NiPc, PPDA-NiPc and DAB-NiPc frameworks are approximately 1.55 nm, 2.11 nm and 2.74 nm, respectively, which is consistent with the simulated results after optimizing the geometric conformation by HyperChem software; additionally, the specific surface areas are 382, 471 and 575 m2 g−1 respectively. As the pore size of the frame increases, the surface area of the material increases accordingly, resulting in different electrochemical behaviors. The initial capacities of the NA-NiPc, PPDA-NiPc and DAB-NiPc electrodes in lithium-ion batteries are 422, 469 and 566 mAh/g, respectively, and after 700 cycles, the capacities remain at 557, 670 and 941 mAh/g, demonstrating capacity retention rates of 131.8%, 142.9% and 166%, respectively, at a current density of 100 mA/g. Even at a high current density of 2 A/g, high specific capacities of 385, 512 and 767 mAh/g can still be observed. Moreover, the use of the NA-NiPc, PPDA-NiPc and DAB-NiPc electrodes in sodium-ion batteries also display excellent behaviors, such as high capacities, stable cycling performances and excellent rate capabilities. With increasing framework porosity, the performances of both lithium-ion and sodium-ion batteries gradually improve, fully indicating that the size of the framework is the key factor in determining the performance of a battery.