Transition-Metal-Triggered High-Efficiency Lithium Ion Storage via Coordination Interactions with Redox-Active Croconate in One-Dimensional Metal–Organic Anode Materials

Abstract

Coordination polymers (CPs) have powerful competence as anode materials for lithium-ion batteries (LIBs) owing to their structural diversity, tunable functionality, and facile and mild synthetic conditions. Here, we show that two isostructural one-dimensional croconate-based CPs, namely, [M(CO)(HO)] (M = Mn for 1 and Co for 2; CO = croconate dianion), can work as high-performance electrode materials for rechargeable LIBs. By means of the coordination between the redox-active transition metal ion and the ligand, the anode materials were stable in the electrolyte and showed high capacities, impressive rate capabilities, and excellent cycling performance during the discharging/charging processes. The chain-based supramolecular structures of the CPs also make them stand out from a crowd of porous three-dimensional molecular materials due to their free channels between the chains for lithium ion diffusion. When tested in a voltage window of 0.01-2.4 V at 100 mA g, CPs 1 and 2 demonstrated high discharge specific capacities of 729 and 741 mA h g, respectively. The synergistical redox reactions on both metal centers and the organic moieties play a crucial role in the high electrochemical performance of CPs 1 and 2. After undergoing elevated discharging/charging rates to 2 A g, the electrodes could finally recover their capabilities as those in the initial stage when the current rate was back to 100 mA g, indicating excellent rate performance and outstanding cycling stabilities of the materials.

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

“…However, unlike the reported organic electrodes with the active lithium-reacted CO/CN/CC units, most of the functional groups (CC or CN) in the MOCP structure are inactive for lithium storage, which is probably ascribed to its orderly stacking structure of MOCP without sufficient exposed surface and/or the coordination involvements of these groups. It results in the unsatisfactory electrochemical performance of MOCP electrodes for lithium-ion batteries, especially with low reversible capacities. − For example, the metal–organic hybrid compounds based on terephthalic acid (BDC) ligand has been widely explored and reported for Li-ion battery electrode materials; − however, it is not optimistic that fewer exposed active sites and inactive metal centers result in a lower specific capacity for the M-BDC-MOF (M = Co, Fe, Ni et al . ). − More efforts should be devoted to the exploration of the new structures and architectural design of MOCPs with more exposed surfaces and boosted active lithium-storage functional groups, in order to maximize the electrochemical properties of the MOCP structures and extend their practical application for energy-storage.…”

Strategies to improve electrochemical performances of pristine metal‐organic frameworks‐based electrodes for lithium/sodium‐ion batteries

“…Nowadays, most MOF materials used in electrochemical energy storage devices take multivalent transitional metal as the metal center 122,123 . Transition metals, such as Fe, Co, and Ni are cheap and distributed widely in the earth, and transition metal ions have more coordination numbers when coordinating with organic ligands, which provides conditions for more creative MOF synthesis.…”

Reversible Energy Storage in Layered Copper-Based Coordination Polymers: Unveiling the Influence of the Ligand’s Functional Group on Their Electrochemical Properties

“…With a plethora of different possibilities to form redox-active coordination polymers, a new family of coordination polymers with the formula unit (M 2+ ) 3 (L 3– ) 2 and kagome-type layered structure has recently been reported as electrode materials for various battery chemistries, including Li ions, Na ions, and Zn–air. − Particularly, the Ni 3 (HIB) 2 coordination polymer was reported as a multielectron cathode material for Li-ion batteries with capacities up to 150 mA h g –1 and long cycling stability . These (M 2+ ) 3 (L 3– ) 2 class of materials with a kagome-type structure present hexasubstituted benzene ligands which are coordinated to three metal ions in a square-planar coordination geometry, forming a two-dimensional layered structure of corner-sharing triangles, with the layers packed in parallel in eclipse, stacked, or intermediate slipped configurations (Figure ).…”

“…With a plethora of different possibilities to form redox-active coordination polymers, 26 a new family of coordination polymers with the formula unit (M 2+ ) 3 (L 3− ) 2 and kagometype layered structure has recently been reported as electrode materials for various battery chemistries, including Li ions, Na ions, and Zn−air. 27−29 Particularly, the Ni 3 (HIB) 2 coordination polymer was reported as a multielectron cathode material for Li-ion batteries with capacities up to 150 mA h g −1 and long cycling stability.…”