Mn-doped Co₂(OH)₃Cl xerogels with 3D interconnected mesoporous structures as lithium ion battery anodes with improved electrochemical performance

Abstract

Considering the merits of 3D mesoporous interconnected structures with large surface area of xerogel and high theoretical capacity of Co 2 (OH) 3 Cl incorporating simultaneously both chlorine and hydroxyl functional groups, it is of greatly fundamental importance and challenge to tune porous structure, surface area, and functionally doping to enhance the electrochemical performance of Co 2 (OH) 3 Cl xerogel anodes for lithium ion batteries (LIBs). Herein, we for the first time report Mn-doped Co 2 (OH) 3 Cl 3D mesoporous xerogels assembled from nanoparticles via one-step sol-gel method. The effect of Mn doping on the microstructures, surface area, charge transfer kinetics, and electrochemical performance of Mn-doped Co 2 (OH) 3 Cl xerogels are systematically investigated. It is shown that 4%Mn-doped Co 2 (OH) 3 Cl xerogels display excellent electrochemical performance, showing a superior capacity of 1377 mAh g −1 after 50 cycles at a current density of 100 mA g -1 . Even when the current density increases to 1600 mA g -1 , it still maintains the capacity of 824 mAh g -1 . The great enhancement on electrochemical performance can be mainly due to the uniquely special 3D hierarchically porous interconnected xerogel structure with high surface area, the enhancement of the electric conductivity and charge transfer kinetics, and the activated redox reaction kinetics related to LiOH and LiCl for the Mn-doped Co 2 (OH) 3 Cl xerogels.

Hierarchitecture Co 2 (OH) 3 Cl@FeCo 2 O 4 composite as a novel and high‐performance electrode material applied in supercapacitor

“…The fitting Co 2p peaks at 780.0 eV and 795.5 eV ascribed to Co 3+ , while 781.3 eV and 796.7 eV ascribed to Co 2+ . The results have the agreement with reported study of Co 2 (OH) 3 Cl and FeCo 2 O 4 . In high‐resolution O 1 second region (Figure 2(C)), the result is deconvoluted into three Gaussian peaks at 529.8 eV, 531.3 eV and 532.4 eV, indexing the O in metal‐Oxygen bond, combination of hydroxyl group (O‐H) and physically adsorbed and chemisorbed water, respectively .…”

“…The results have the agreement with reported study of Co 2 (OH) 3 Cl and FeCo 2 O 4 . 44,57 In highresolution O 1 second region (Figure 2(C)), the result is deconvoluted into three Gaussian peaks at 529.8 eV, 531.3 eV and 532.4 eV, indexing the O in metal-Oxygen bond, combination of hydroxyl group (O-H) and physically adsorbed and chemisorbed water, respectively. 44,58 The two fitting peaks at 198.0 eV and 199.6 eV can be associated with the Cl 2p ( Figure 2D).…”

“…Co 2 (OH) 3 Cl with the pyrochlore‐like crystal structure has general formula as Co(OH) 2‐n (A n‐ ) (A = Cl − ,NO 3 − , SO 4 2− , CO 3 2− ). Co 2 (OH) 3 Cl is usually considered as a solid solution of CoCl 2 and Co(OH) 2 in composition and the hydroxyl‐rich phase in structure . It has been extensively studied in magnetic field as a special magnetic geometrically frustrated material .…”

“…Co 2 (OH) 3 Cl is usually considered as a solid solution of CoCl 2 and Co(OH) 2 in composition and the hydroxyl-rich phase in structure. [41][42][43][44][45][46] It has been extensively studied in magnetic field as a special magnetic geometrically frustrated material. 46,47 However, there are little research in electrochemical filed as supercapacitor electrodes.…”

Co-doped Ni hydroxide and oxide nanosheet networks: laser-assisted synthesis, effective doping, and ultrahigh pseudocapacitor performance

“…1(e), the Co 2p XPS spectrum of the sample exhibits two peaks, at 781.3 and 796.8 eV, corresponding to the characteristic Co 2p 3/2 and Co 2p 1/2 peaks, with a spin-energy separation of 15.7 eV, demonstrating the presence of Co 2+ . 37,38 In order to further conrm the XRD and XPS results, FTIR is used to characterize sample CN-0.1, as shown in Fig. 1(f).…”