CoFe–Cl Layered Double Hydroxide: A New Cathode Material for High‐Performance Chloride Ion Batteries

Abstract

Chloride ion batteries (CIBs) are regarded as promising energy storage systems due to their large theoretical volumetric energy density, high abundance, and low cost of chloride resources. Herein, the synthesis of CoFe layered double hydroxide in the chloride form (CoFe-Cl LDH), for use as a new cathode material for CIBs, is demonstrated for the first time. The CoFe-Cl LDH exhibits a maximum capacity of 239.3 mAh g −1 and a high reversible capacity of ≈160 mAh g −1 over 100 cycles. The superb Cl − ion storage of CoFe-Cl LDH is attributed to its unique topochemical transformation property during the charge/discharge process: a reversible intercalation/deintercalation of Cl − ions in cathode with slight expansion/contraction of basal spacing, accompanied by chemical state changes in Co 2+ /Co 3+ and Fe 2+ /Fe 3+ couples. First-principles calculations reveal that CoFe-Cl LDH is an excellent Cl − ion conductor, with extremely low energy barriers (0.12−0.25 eV) for Cl − diffusion. This work opens a new avenue for LDH materials as promising cathodes for anion-type rechargeable batteries, which are regarded as formidable competitors to traditional metal ion-shuttling batteries.

Etching‐Doping Sedimentation Equilibrium Strategy: Accelerating Kinetics on Hollow Rh‐Doped CoFe‐Layered Double Hydroxides for Water Splitting

“…As illustrated in Figure S13b in the Supporting Information, after Rh doping, the intercalated carbonates are still in the LDHs, which are observed at 1380 and 1680 cm −1 . [25,33,34] Furthermore, the peaks at ≈3400 and 1135 cm −1 belong to hydroxyl (OH − ) and sulfate (SO 4 2− ) ions, respectively. [33,35]…”

Ultralong‐Life Chloride Ion Batteries Achieved by the Synergistic Contribution of Intralayer Metals in Layered Double Hydroxides

“…However, the unsatisfactory cycling performance and structural instability of cathode materials hinder their practical application. [12] Since the first proof that the reversible shuttle of chloride ions between a metal chloride cathode (BiCl 2 , CoCl 2 , and VCl 3 ) and a lithium anode was proposed by Zhao et al, [5] metal oxychlorides [6,13] and chloride-doped organic polymers, [14,15] such as PPy and PANI, have been subsequently demonstrated as possible electrode materials in CIBs. The Ni 2 V 0.9 Al 0.1 -Cl LDH is capable of delivering a high initial capacity of 312.2 mAh g −1 at 200 mA g −1 and an ultralong life over 1000 cycles (with a capacity higher than 113.8 mAh g −1 ).…”

“…In this work, layered double hydroxides (LDHs), which consist of a trimetallic NiVAl hydroxide host matrix and interlayer Cl − , are demonstrated to be high-performance cathode materials for CIBs. [16][17][18][19][20] In our previous work, [12] we have proposed for the first time that a CoFe LDH with chloride ions in its interlayer could exhibit an outstanding ability of Cl − insertion/deinsertion resulting from its 2D diffusion channel for Cl − transfer and the unique topochemical transformation characteristic of the LDH structure. Such a long cycling life exceeds that of any reported CIBs.…”

“…[11] In addition, the abundance of chloride-containing materials and their availability worldwide not only lower the costs but also enable manufacturing all over the world. [12] Since the first proof that the reversible shuttle of chloride ions between a metal chloride cathode (BiCl 2 , CoCl 2 , and VCl 3 ) and a lithium anode was proposed by Zhao et al, [5] metal oxychlorides [6,13] and chloride-doped organic polymers, [14,15] such as PPy and PANI, have been subsequently demonstrated as possible electrode materials in CIBs. [12] Since the first proof that the reversible shuttle of chloride ions between a metal chloride cathode (BiCl 2 , CoCl 2 , and VCl 3 ) and a lithium anode was proposed by Zhao et al, [5] metal oxychlorides [6,13] and chloride-doped organic polymers, [14,15] such as PPy and PANI, have been subsequently demonstrated as possible electrode materials in CIBs.…”

“…[16][17][18][19][20] In our previous work, [12] we have proposed for the first time that a CoFe LDH with chloride ions in its interlayer could exhibit an outstanding ability of Cl − insertion/deinsertion resulting from its 2D diffusion channel for Cl − transfer and the unique topochemical transformation characteristic of the LDH structure. [16][17][18][19][20] In our previous work, [12] we have proposed for the first time that a CoFe LDH with chloride ions in its interlayer could exhibit an outstanding ability of Cl − insertion/deinsertion resulting from its 2D diffusion channel for Cl − transfer and the unique topochemical transformation characteristic of the LDH structure.…”