title: Crystal Engineering of Naphthalenediimide-Based Metal-Organic Frameworks: Structure-Dependent Lithium Storage.
abstract: Metal-organic frameworks (MOFs) possess great structural diversity because of the flexible design of linker groups and metal nodes. The structure-property correlation has been extensively investigated in areas like chiral catalysis, gas storage and absorption, water purification, energy storage, etc. However, the use of MOFs in lithium storage is hampered by stability issues, and how its porosity helps with battery performance is not well understood. Herein, through anion and thermodynamic control, we design a series of naphthalenediimide-based MOFs 1-4 that can be used for cathode materials in lithium-ion batteries (LIBs). Complexation of the N,N'-di(4-pyridyl)-1,4,5,8-naphthalenediimide (DPNDI) ligand and CdX2(X = NO3-or ClO4-) produces complexes MOFs 1 and 2 with a one-dimensional (1D) nonporous network and a porous, noninterpenetrated two-dimensional (2D) square-grid structure, respectively. With the DPNDI ligand and Co(NCS)2, a porous 1D MOF 3 as a kinetic product is obtained, while a nonporous, noninterpenetrated 2D square-grid structure MOF 4 as a thermodynamic product is formed. The performance of LIBs is largely affected by the stability and porosity of these MOFs. For instance, the initial charge-discharge curves of MOFs 1 and 2 show a specific capacity of ∼47 mA h g-1with a capacity retention ratio of >70% during 50 cycles at 100 mA g-1, which is much better than that of MOFs 3 and 4. The better performances are assigned to the higher stability of Cd(II) MOFs compared to that of Co(II) MOFs during the electrochemical process, according to X-ray diffraction analysis. In addition, despite having the same Cd(II) node in the framework, MOF 2 exhibits a lithium-ion diffusion coefficient (DLi) larger than that of MOF 1 because of its higher porosity. X-ray photoelectron spectroscopy and Fourier transform infrared analysis indicate that metal nodes in these MOFs remain intact and only the DPNDI ligand undergoes the revisible redox reaction during the lithiation-delithiation process.
authors: SZU-NUS Collaborative Innovation Center for Optoelectronic Science & Technology, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University , Shenzhen 518060, China.|Department of Chemistry, Centre for Advanced 2D Materials (CA2DM), Graphene Research Centre, National University of Singapore , 3 Science Drive 3, Singapore 117543.
authors: Bingbing
authors: B
authors: Tian
authors: Department of Chemistry, Centre for Advanced 2D Materials (CA2DM), Graphene Research Centre, National University of Singapore , 3 Science Drive 3, Singapore 117543.
authors: Guo-Hong
authors: GH
authors: Ning
authors: SZU-NUS Collaborative Innovation Center for Optoelectronic Science & Technology, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University , Shenzhen 518060, China.|Department of Chemistry, Centre for Advanced 2D Materials (CA2DM), Graphene Research Centre, National University of Singapore , 3 Science Drive 3, Singapore 117543.
authors: Qiang
authors: Q
authors: Gao
authors: Department of Chemistry, Centre for Advanced 2D Materials (CA2DM), Graphene Research Centre, National University of Singapore , 3 Science Drive 3, Singapore 117543.
authors: Li-Min
authors: LM
authors: Tan
authors: Department of Chemistry, Centre for Advanced 2D Materials (CA2DM), Graphene Research Centre, National University of Singapore , 3 Science Drive 3, Singapore 117543.
authors: Wei
authors: W
authors: Tang
authors: Department of Chemistry, Centre for Advanced 2D Materials (CA2DM), Graphene Research Centre, National University of Singapore , 3 Science Drive 3, Singapore 117543.
authors: Zhongxin
authors: Z
authors: Chen
authors: SZU-NUS Collaborative Innovation Center for Optoelectronic Science & Technology, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University , Shenzhen 518060, China.|Department of Chemistry, Centre for Advanced 2D Materials (CA2DM), Graphene Research Centre, National University of Singapore , 3 Science Drive 3, Singapore 117543.
authors: Chenliang
authors: C
authors: Su
authors: SZU-NUS Collaborative Innovation Center for Optoelectronic Science & Technology, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University , Shenzhen 518060, China.|Department of Chemistry, Centre for Advanced 2D Materials (CA2DM), Graphene Research Centre, National University of Singapore , 3 Science Drive 3, Singapore 117543.
authors: Kian Ping
authors: KP
authors: Loh
keywords: cathode materials; crystal engineering; lithium-ion batteries; lithium-ion diffusion coefficient (DLi); metal−organic frameworks; structural features