High Anodic Performance of Co 1,3,5-Benzenetricarboxylate Coordination Polymers for Li-Ion Battery

Abstract

We report the designed synthesis of Co 1,3,5-benzenetricarboxylate coordination polymers (CPs) via a straightforward hydrothermal method, in which three kinds of reaction solvents are selected to form CPs with various morphologies and dimensions. When tested as anode materials in Li-ion battery, the cycling stabilities of the three CoBTC CPs at a current density of 100 mA g(-1) have not evident difference; however, the reversible capacities are widely divergent when the current density is increased to 2 A g(-1). The optimized product CoBTC-EtOH maintains a reversible capacity of 473 mAh g(-1) at a rate of 2 A g(-1) after 500 galvanostatic charging/discharging cycles while retaining a nearly 100% Coulombic efficiency. The hollow microspherical morphology, accessible specific area, and the absence of coordination solvent of CoBTC-EtOH might be responsible for such difference. Furthermore, the ex situ soft X-ray absorption spectroscopy studies of CoBTC-EtOH under different states-of-charge suggest that the Co ions remain in the Co(2+) state during the charging/discharging process. Therefore, Li ions are inserted to the organic moiety (including the carboxylate groups and the benzene ring) of CoBTC without the direct engagement of Co ions during electrochemical cycling.

Bimetallic zeolite imidazolate framework for enhanced lithium storage boosted by the redox participation of nitrogen atoms

“…Recently, conjugated carboxylates based MOFs, such as Co-BDC [7,8], Mn-BDC [9], Fe-BDC [10,11], Mn-BTC [12], CoBTC [13], Cu-BTC [14] and Fe-BTC [15], are being employed in LIBs and have attracted tremendous attention for their high performances. Further researches indicate that lithium is inserted into organic moiety in these MOFs and it is deduced that the electron withdrawing effect of the conjugated carboxylates should be the main impetus in storing lithium-ions [12][13][14][15][16][17][18][19]. However, MOFs-based electrodes with other kinds of organic linkers are seldom employed in LIBs for the lack of highly-active lithiation sites.…”

Confined Transformation of Organometal‐Encapsulated MOFs into Spinel CoFe2O4/C Nanocubes for Low‐Temperature Catalytic Oxidation

“…However, the organometallics post‐synthetic modification led FeBTC to possess new crystal structure with clear lattice fringes of 0.226 and 0.214 nm (Figure 1g,h). By analysis (Figure 2b), a sharp characteristic peak of sample Co(OAc) 2 /FeBTC was similar to the crystal structure of cobalt‐benzenetricarboxylic acid compounds 32. According to the comparison on FTIR results of FeBTC and Co(OAc) 2 /FeBTC (Figure 2c), the typical vibration peaks at 1271 and 1716 cm −1 assigned to CO and CO stretching disappeared, which well demonstrated that the high crystallinity composites with small size was formed due to the strong interaction between cobalt acetate and organic ligands of FeBTC.…”

MOF‐Derived CuS@Cu‐BTC Composites as High‐Performance Anodes for Lithium‐Ion Batteries

“…Generally, nanostructures with smaller size facilitate the penetration of electrolyte into the electrode, shortening the diffusion path of lithium ions. In addition, it has been demonstrated that the BTC ligands in M‐BTC (M = Cu, Co, Mn) can also contribute to the enhancement of capacities . Therefore, the Cu‐BTC species with moderate content in the composites is beneficial to achieve optimal electrochemical properties.…”

“…Because of the tunable supramolecular components (inorganic and organic species), MOFs are particularly suitable for the electrochemical application. Recently, several groups reported the effect of carboxylate ligands in M‐BTC materials (M = Cu, Co, Mn) on lithium‐storage performances . The experimental and theoretical results strongly revealed that the high lithium‐storage abilities of M‐BTC materials can be ascribed to the multiple electron redox conversion of both metal ions and BTC ligands, as well as the reversible insertion/desertion of Li + ions into/from the benzene rings of BTC.…”

“…Recently, several groups reported the effect of carboxylate ligands in M-BTC materials (M = Cu, Co, Mn) on lithium-storage performances. [26][27][28] The experimental and theoretical results strongly revealed that the high lithium-storage abilities of M-BTC materials can be ascribed to the multiple electron redox conversion of both metal ions and BTC ligands, as well as the reversible insertion/desertion of Li + ions into/from the benzene rings of BTC. However, most of MOFs without any structural modifications are considered typically as poor conductors because of the poor overlap between p and d orbitals of metal ions as well as electron insulation properties of organic ligands.…”