Carbonyl Functional Group Modified Metal–Organic Coordination Polymer with Improved Lithium-Storage Performance

Abstract

Exploration of the structures and architectural design of crystalline porous metal−organic coordination polymer (MOCP) materials with boosted active lithium-storage functional groups is still an urgent requirement for MOCP structures with improved lithium-storage properties when applied as the electrodes for next-generation lithium-ion batteries. Herein, we synthesize a carbonyl functional group modified Co-based metal−organic coordination polymer (Co-BDBA-MOCP) via a one-step facile microwave-assisted solvothermal method and apply it as the electrode material for a lithium-ion battery for the first time. The unique petals-assembled rose-shaped morphology endows the Co-BDBA-MOCP structure with a more exposed surface and porous structure, which can provide more active sites and facilitate fast Liion transport. Thus, the boosted lithium-reaction activation of the Co 2+ centers, the CC groups of the benzene rings, and the modified CO groups in the structure and further the extremely enhanced electrochemical performance can be achieved for the Co-BDBA-MOCP electrode. This electrode delivers an initial reversible capacity of 1401 mAh g −1 at a current density of 100 mA g −1 with ∼1150 mAh g −1 retained after 100 cycles, and a large reversible capacity of 743 mAh g −1 after 350 cycles at a large current of 500 mA g −1 . The exploration of the active lithium reaction units modified metal−organic frameworks with more activated functional groups for lithium storage would further shed light on high-performance electrodes for next-generation rechargeable batteries.

Rational Construction of Yolk–Shell Bimetal-Modified Quinonyl-Rich Covalent Organic Polymers with Ultralong Lithium-Storage Mechanism

“…As for anode materials of LIBs, the first three cyclic voltammetry (CV) plots of all samples were measured. As observed for the Co@2AQ-MnO 2 sample (Figure 4a), the cathodic peaks at ∼1.3, 1.0, 0.7, and 0.4 V can be attributed to the reduction of CO units, the irreversible formation of a solid electrolyte interphase (SEI) film, the redox reaction of Co 2+ /Co, 58 and the reduction of MnO 2 based on MnO 2 + 4Li + + 4e − = Mn + 2Li 2 O, 56,57 respectively. The corresponding anodic peaks observed at around 2.1, 1.4, and 1.2 V indicate the reversible lithium-storage reaction on CO units, Co 2+ /Co, and MnO 2 /Mn.…”

“…Moreover, the peaks at 780.8 and 796.8 eV correspond to Co 2+ , and the appearance of peaks at 798.5 and 783.0 eV can be ascribed to the coordination between cobalt(II) and 2AQ. 58,59 The crystalline structure of these samples was also investigated by the X-ray diffraction (XRD) technique. As illustrated in Figure S4 .…”

“…In Figure f, the high-resolution Co 2p XPS peaks at 780.8 eV (dark pink) and 783.0 eV (blue) consist of the spin–orbit splitting values of Co 2p 3/2 , and the corresponding peaks at 796.8 eV (light pink) and 798.5 eV (orange) can be attributed to the spin–orbit splitting values of Co 2p 1/2 . Moreover, the peaks at 780.8 and 796.8 eV correspond to Co 2+ , and the appearance of peaks at 798.5 and 783.0 eV can be ascribed to the coordination between cobalt­(II) and 2AQ. , The crystalline structure of these samples was also investigated by the X-ray diffraction (XRD) technique. As illustrated in Figure S4, diffraction peaks at 5.0°, 21.9°, and 40.7° can be assigned to the lattice planes of 2AQ.…”

Boosted π-Li Cation Effect in the Stabilized Small Organic Molecule Electrode via Hydrogen Bonding with MXene

“…As illuminated in Figure b for the TBAP@D-Ti 3 C 2 T x electrode, the downward or upward trends suggests the depletion of pre-existing functional groups or the generation of new functional groups. During the first discharging process, the decrease of the peak intensity of the CO (at ∼1675 cm –1 ) and CC groups (at 1450–1550 cm –1 ) can be detected, while the peaks of C–O (at ∼1270 cm –1 ) and C–C (at ∼1310 cm –1 ) groups become increased . It can be ascribed to the reduction of CO and CC units during the lithiation process.…”

“…During the first discharging process, the decrease of the peak intensity of the CO (at ∼1675 cm −1 ) and CC groups (at 1450−1550 cm −1 ) can be detected, while the peaks of C−O (at ∼1270 cm −1 ) and C−C (at ∼1310 cm −1 ) groups become increased. 45 It can be ascribed to the reduction of C O and CC units during the lithiation process. Meanwhile, the growth peak at ∼558 cm −1 during the lithiation process, which can be ascribed to the formation of the O−Li band, also indicates the reaction between CO and C−O groups.…”