Suppressing capacity fading and voltage decay of Li-rich layered cathode material by a surface nano-protective layer of CoF2 for lithium-ion batteries

Chong, Shaokun; Chen, Yuanzhen; Yan, Wuwei; Guo, Shengwu; Tan, Qiang; Wu, Yue; Jiang, Tao; Liu, Yongning

doi:10.1016/j.jpowsour.2016.09.028

Cited by 86 publications

(38 citation statements)

References 47 publications

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“…This can be due to incomplete charge-discharge reactions limited by cycling voltage loop fixed to be between 0.4 and 4.0 V vs. Li + /Li to minimize electrolyte degradation and by the slowness of conversion reactions. In contrast to previously reported results [11,[25][26][27][28][29][30] related to metal transition fluorides, our results demonstrated a good electrochemical stability of CNT-MnF 2 nanocomposites cathodes. The excellent electrochemical properties of CNT-MnF 2 nanocomposites as cathode material for Li-ion batteries suggests that the infiltration of MnF 2 nanoparticles inside CNT structure accelerates charge and Li ions transfer during charge-discharge cycles by keeping a good connectivity and an unceasing electrical contact between the conductive CNT support and the weakly-conductive active MnF 2 nanomaterials which results in high capacity and durable cyclability.…”

Section: Resultscontrasting

confidence: 99%

“…CNT-MnF 2 nanocomposites cathode displayed CE values very close to 100% in long cycles, indicating the high reversibility of electrochemical conversion reactions. It seems that the joint assembly between the flexible and conductive CNT fabric facilitates the charge transfer and absorbs the volumetric changes during conversion reactions [21][22][23][24][25][26][27][28][29][30], which maintains the specific capacity of CNT-MnF 2 cathodes during charge-discharge cycles. The measured specific capacity, 388 mAh/g, was about 67% the theoretical capacity of pure MnF 2 material (577 mAh/g).…”

Section: Resultsmentioning

confidence: 99%

“…Recently, transition-metal fluorides (TMFs) have been used as cathode materials in LIBs, and achieved high capacities and high energy densities [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. The oxidation state of the metal in TMFs involves the transfer of multiple electrons/lithium ions per formula unit leading to higher theoretical volumetric capacity (up to ≈2200 mAh/cm 3 ) and higher theoretical potential (up to ≈3.5 V vs Li/Li + ).…”

Section: Introductionmentioning

confidence: 99%

“…Recently, several attempts to prepare nano-sized metal fluorides using pyrolysis, precipitation and supercritical-fluid technologies showed poor electrochemical performance after few cycles due to the inhomogeneity of structure and the composition [11][12][13][14][15][16][25][26][27][28][29]. More recently, Wang et al [30] have demonstrated that the incorporation of CoF 2 nanoparticles inside CNTs fabric prepared in situ by annealing of CNT-CoSiF 6 composites enhanced the capacity of Li-ion batteries; however the capacity did not reach the theoretical value.…”

Section: Introductionmentioning

confidence: 99%

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Surfactant-aided impregnation of MnF2 into CNT fabrics as cathode material with high electrochemical performance for lithium ion batteries

2018

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MnF 2 infiltrated-CNT fabrics was prepared by surfactant-aided impregnation of MnSiF 6 precursors in acidtreated CNT fabric followed by annealing MnSiF 6 -loaded CNT fabric. The structural and morphological characterizations by X-ray diffraction, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) confirmed the formation of MnF 2 nanoparticles (average size: 20-30 nm) within CNT fabric structure. Galvanostatic charge-discharge tests of CNT-MnF 2 nanocomposite fabrics showed excellent electrochemical performance and good cycle stability between 0.4 and 4.0 V vs Li/Li + . A specific capacity of 388 mAh/g was measured at 0.1C for CNT-MnF 2 fabric with 70% MnF 2 loading after 100 cycles. Stable cyclability and good rate performance were obtained at high charge-discharge cycling rates. MnF 2 loading largely affect the performance of MnF 2 infiltrated-CNT fabrics cathodes when lower than 70% MnF 2 loaded-CNT fabrics were prepared. It can be concluded that nano-sized active materials infiltrated inside conductive carbon matrix in optimized content can lead to rapid kinetics and stable performance for flexible metal fluoride-based cathode materials.

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Section: Resultscontrasting

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Surfactant-aided impregnation of MnF2 into CNT fabrics as cathode material with high electrochemical performance for lithium ion batteries

2018

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“…Recently, several attempts to prepare nano‐sized metal fluorides using pyrolysis, precipitation and supercritical‐fluid technologies showed poor electrochemical performance after few cycles due to the inhomogeneity of structure and the composition . More recently, Wang et al have demonstrated that the incorporation of CoF 2 nanoparticles inside CNTs fabric prepared in situ by annealing of CNT‐CoSiF 6 composites enhanced the capacity of Li‐ion batteries; however the capacity did not reach the theoretical value.…”

Section: Introductionmentioning

confidence: 99%

Hierarchical Nanostructured MWCNT–MnF₂ Composites With Stable Electrochemical Properties as Cathode Material for Lithium Ion Batteries

Bensalah

Turki

Kamand

et al. 2018

Physica Status Solidi (a)

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Multi-walled carbon nanotubes-manganese(II) fluoride (MWCNT-MnF 2 ) composite was prepared by a simple two-step method. In the first step, a wet chemistry reaction between manganese (II) nitrate, Mn(NO 3 ) 2 , and hexafluoroslicic acid, H 2 SiF 6 , produces manganese(II) hexafluorosilicate (MnSiF 6 ). The thermal decomposition of MnSiF 6 in presence of MWCNTs at 400 C under argon atmosphere releases SiF 4 gas and forms MWCNT-MnF 2 composite. Powder X-ray diffraction, Raman spectroscopy, and scanning electron microscopy confirmed the formation of pure phases of MnF 2 nanoparticles with rutile crystalline structure with no impurity phases. MnF 2 nanoparticles were dispersed among MWCNTs networks and partially decorating MWCNTs forming a hierarchically nanostructured MWCNT-MnF 2 composite. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy tests showed that the MWCNT-MnF 2 composite electrode underwent electrochemical lithiation/delithiation reactions with enhanced reversibility and stabilized solid-electrolyte interface (SEI) during cycling. Charge-discharge tests demonstrated that the MWCNT-MnF 2 electrode displayed an irreversible specific capacity in the first cycle mainly linked to the decomposition of the electrolyte and the formation of the SEI film. After 100 cycles, a charge specific capacity of 480 mAh g À1 MnF 2 was measured (80% of the initial capacity) with high coulombic efficiency (CE) (%100%), indicating the high reversibility of electrochemical conversion reactions. X-ray photoelectron spectroscopy, XRD, and SEM-EDX analyses for non-cycled and fully discharged MWCNT-MnF 2 electrodes confirmed the irreversible lithiation of MnF 2 into Mn and LiF during the ten first charge-discharge cycles. The higher electrochemical performance of the composite electrode compared to pure MnF 2 can be attributed to the hierarchical structure of MWCNT-MnF 2 , which is capable to assimilate the volume changes, stabilize the solidelectrolyte interface (SEI), and facilitate Li þ ions and electrons transfer.

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In Situ Surface Self‐Reconstruction Strategies in Li‐Rich Mn‐Based Layered Cathodes for Energy‐Dense Li‐Ion Batteries

Gou

Hao

et al. 2022

Adv Funct Materials

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Lithium‐rich manganese‐based layered oxides (LROs) are standing out as cathode materials of lithium‐ion batteries (LIBs) due to merits on both capacity (>250 mAh g−1) and operation voltage (≈3.6 V). However, the applications of LROs are plagued by almost inevitable degradation of structure, in which electrode surface bears the brunt as the primacy barrier for Li+ transport. Plenty of surface modification strategies are proposed to stabilize the structure and in situ self‐reconstruction strategies with atomic level connection to bulk structures provide robust layers to prevent the degradation. Herein, a critical review focusing on in situ surface reconstruction of LROs is summarized. It is started from the overview of LROs and then the surface challenges including lattice oxygen release, phase transformation, transition metal ions dissolution, and interfacial side reactions are further discussed. In situ self‐reconstruction strategies are emphasized to alleviate the performance degradation of LROs, from creating oxygen vacancies to synthesizing layered‐spinel or layered‐rocksalt heterogeneous structures. Among these approaches, synthesis and characterization methods, formation mechanisms and roles to stabilize the structures are highlighted. Finally, the prospects from the aspects of precise/large scale preparations, interphase design between electrolytes and electrodes, and in‐operando characterization approaches for the commercialization of LROs are provided.

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Suppressing capacity fading and voltage decay of Li-rich layered cathode material by a surface nano-protective layer of CoF2 for lithium-ion batteries

Cited by 86 publications

References 47 publications

Surfactant-aided impregnation of MnF2 into CNT fabrics as cathode material with high electrochemical performance for lithium ion batteries

Surfactant-aided impregnation of MnF2 into CNT fabrics as cathode material with high electrochemical performance for lithium ion batteries

Hierarchical Nanostructured MWCNT–MnF₂ Composites With Stable Electrochemical Properties as Cathode Material for Lithium Ion Batteries

In Situ Surface Self‐Reconstruction Strategies in Li‐Rich Mn‐Based Layered Cathodes for Energy‐Dense Li‐Ion Batteries

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Suppressing capacity fading and voltage decay of Li-rich layered cathode material by a surface nano-protective layer of CoF2 for lithium-ion batteries

Cited by 86 publications

References 47 publications

Surfactant-aided impregnation of MnF2 into CNT fabrics as cathode material with high electrochemical performance for lithium ion batteries

Surfactant-aided impregnation of MnF2 into CNT fabrics as cathode material with high electrochemical performance for lithium ion batteries

Hierarchical Nanostructured MWCNT–MnF2 Composites With Stable Electrochemical Properties as Cathode Material for Lithium Ion Batteries

In Situ Surface Self‐Reconstruction Strategies in Li‐Rich Mn‐Based Layered Cathodes for Energy‐Dense Li‐Ion Batteries

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Hierarchical Nanostructured MWCNT–MnF₂ Composites With Stable Electrochemical Properties as Cathode Material for Lithium Ion Batteries