scholarly journals Synthesis of Si/Fe2O3-Anchored rGO Frameworks as High-Performance Anodes for Li-Ion Batteries

2021 ◽  
Vol 22 (20) ◽  
pp. 11041
Author(s):  
Yajing Yan ◽  
Yanxu Chen ◽  
Yongyan Li ◽  
Xiaoyu Wu ◽  
Chao Jin ◽  
...  

By virtue of the high theoretical capacity of Si, Si-related materials have been developed as promising anode candidates for high-energy-density batteries. During repeated charge/discharge cycling, however, severe volumetric variation induces the pulverization and peeling of active components, causing rapid capacity decay and even development stagnation in high-capacity batteries. In this study, the Si/Fe2O3-anchored rGO framework was prepared by introducing ball milling into a melt spinning and dealloying process. As the Li-ion battery (LIB) anode, it presents a high reversible capacity of 1744.5 mAh g−1 at 200 mA g−1 after 200 cycles and 889.4 mAh g−1 at 5 A g−1 after 500 cycles. The outstanding electrochemical performance is due to the three-dimensional cross-linked porous framework with a high specific surface area, which is helpful to the transmission of ions and electrons. Moreover, with the cooperation of rGO, the volume expansion of Si is effectively alleviated, thus improving cycling stability. The work provides insights for the design and preparation of Si-based materials for high-performance LIB applications.

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 441 ◽  
Author(s):  
Jinyun Liu ◽  
Jiawei Long ◽  
Sen Du ◽  
Bai Sun ◽  
Shuguang Zhu ◽  
...  

Among many types of batteries, Li-ion and Li-S batteries have been of great interest because of their high energy density, low self-discharge, and non-memory effect, among other aspects. Emerging applications require batteries with higher performance factors, such as capacity and cycling life, which have motivated many research efforts on constructing high-performance anode and cathode materials. Herein, recent research about cathode materials are particularly focused on. Low electron and ion conductivities and poor electrode stability remain great challenges. Three-dimensional (3D) porous nanostructures commonly exhibit unique properties, such as good Li+ ion diffusion, short electron transfer pathway, robust mechanical strength, and sufficient space for volume change accommodation during charge/discharge, which make them promising for high-performance cathodes in batteries. A comprehensive summary about some cutting-edge investigations of Li-ion and Li-S battery cathodes is presented. As demonstrative examples, LiCoO2, LiMn2O4, LiFePO4, V2O5, and LiNi1−x−yCoxMnyO2 in pristine and modified forms with a 3D porous structure for Li-ion batteries are introduced, with a particular focus on their preparation methods. Additionally, S loaded on 3D scaffolds for Li-S batteries is discussed. In addition, the main challenges and potential directions for next generation cathodes have been indicated, which would be beneficial to researchers and engineers developing high-performance electrodes for advanced secondary batteries.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Jinghui Ren ◽  
Zhenyu Wang ◽  
Peng Xu ◽  
Cong Wang ◽  
Fei Gao ◽  
...  

AbstractHigh-energy–density lithium-ion batteries (LIBs) that can be safely fast-charged are desirable for electric vehicles. However, sub-optimal lithiation potential and low capacity of commonly used LIBs anode cause safety issues and low energy density. Here we hypothesize that a cobalt vanadate oxide, Co2VO4, can be attractive anode material for fast-charging LIBs due to its high capacity (~ 1000 mAh g−1) and safe lithiation potential (~ 0.65 V vs. Li+/Li). The Li+ diffusion coefficient of Co2VO4 is evaluated by theoretical calculation to be as high as 3.15 × 10–10 cm2 s−1, proving Co2VO4 a promising anode in fast-charging LIBs. A hexagonal porous Co2VO4 nanodisk (PCVO ND) structure is designed accordingly, featuring a high specific surface area of 74.57 m2 g−1 and numerous pores with a pore size of 14 nm. This unique structure succeeds in enhancing Li+ and electron transfer, leading to superior fast-charging performance than current commercial anodes. As a result, the PCVO ND shows a high initial reversible capacity of 911.0 mAh g−1 at 0.4 C, excellent fast-charging capacity (344.3 mAh g−1 at 10 C for 1000 cycles), outstanding long-term cycling stability (only 0.024% capacity loss per cycle at 10 C for 1000 cycles), confirming the commercial feasibility of PCVO ND in fast-charging LIBs.


2021 ◽  
Vol 14 (02) ◽  
pp. 2150011
Author(s):  
Xiaoyong Fan ◽  
Ruibo Sun ◽  
Jiaxing Han ◽  
Yan Wu ◽  
Lei Gou ◽  
...  

Na3V2(PO[Formula: see text] (NVP) as one typical Na[Formula: see text] super ionic conductor (NASICON) is recognized as an ideal cathode material for ZIBs owing to its promising structural stability that facilitates long cycle, rich vacancies and channels facilitate storing metal ions, high operating potentials to ensure high energy density. However, it still faces poor cyclability and high-rate capacity. Here, three-dimensional networked Na3V2(PO[Formula: see text]/C composite is synthesized by a microemulsion strategy with cetyltrimethyl ammonium bromide (CTAB) as the soft template, and the effect of aging temperature of microemulsion on their morphology and electrochemical performance is investigated. The Na3V2(PO[Formula: see text]/C composite derived from the precursor reacted at 70[Formula: see text]C shows micrometer-size particles assembled by three-dimensional networked nanoplates, facilitating for ions transport and delivers the best electrochemical performance. It displays a high first capacity of 102.2 mAh g[Formula: see text] with 42.3 mAh g[Formula: see text] remained after 5000 stable cycles (capacity retention of 41.4%) at 5 C, a high capacity of 83.2 mAh g[Formula: see text] even the current density is as high as 20 C, which is better than most of the reports.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Haisheng Han ◽  
Yanli Song ◽  
Yongguang Zhang ◽  
Gulnur Kalimuldina ◽  
Zhumabay Bakenov

AbstractIn recent years, the development of lithium-ion batteries (LIBs) with high energy density has become one of the important research directions to fulfill the needs of electric vehicles and smart grid technologies. Nowadays, traditional LIBs have reached their limits in terms of capacity, cycle life, and stability, necessitating their further improvement and development of alternative materials with remarkably enhanced properties. A nitrogen-containing carbon nanotube (N-CNT) host for bimetallic sulfide (NiCo2S4) is proposed in this study as an anode with attractive electrochemical performance for LIBs. The prepared NiCo2S4/N-CNT nanocomposite exhibited improved cycling stability, rate performance, and an excellent reversible capacity of 623.0 mAh g–1 after 100 cycles at 0.1 A g–1 and maintained a high capacity and cycling stability at 0.5 A g–1. The excellent electrochemical performance of the composite can be attributed to the unique porous structure, which can effectively enhance the diffusivity of Li ions while mitigating the volume expansion during the charge–discharge processes.


Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3355
Author(s):  
Mingshan Sun ◽  
Xinan Chen ◽  
Shutian Tan ◽  
Ying He ◽  
Petr Saha ◽  
...  

Herein, a three-dimensional (3D) Fe3O4@C composite with hollow porous structure is prepared by simple solution method and calcination treatment with biomass waste rape pollen (RP) as a carbon source, which is served as an anode of Li-ion capacitor (LIC). The 3D interconnected porous structure and conductive networks facilitate the transfer of ion/electron and accommodate the volume changes of Fe3O4 during the electrochemical reaction process, which leads to the excellent performance of the Fe3O4@C composite electrode. The electrochemical analysis demonstrates that the hybrid LIC fabricated with Fe3O4@C as the anode and activated carbon (AC) as the cathode can operate at a voltage of 4.0 V and exhibit a high energy density of 140.6 Wh kg−1 at 200 W kg−1 (52.8 Wh kg−1 at 10 kW kg−1), along with excellent cycling stability, with a capacity retention of 83.3% over 6000 cycles. Hence, these encouraging results indicate that Fe3O4@C has great potential in developing advanced LICs electrode materials for the next generation of energy storage systems.


2021 ◽  
Author(s):  
yajun JI ◽  
Fei Chen ◽  
Shufen Tan ◽  
Fuyong Ren

Abstract Transition metal oxides are generally designed as hybrid nanostructures with high performance for supercapacitors by enjoying the advantages of various electroactive materials. In this paper, a convenient and efficient route had been proposed to prepare hierarchical coral-like MnCo2O4.5@Co-Ni LDH composites on Ni foam, in which MnCo2O4.5 nanowires were enlaced with ultrathin Co-Ni layered double hydroxides nanosheets to achieve high capacity electrodes for supercapacitors. Due to the synergistic effect of shell Co-Ni LDH and core MnCo2O4.5, the outstanding electrochemical performance in three-electrode configuration was triggered (high area capacitance of 5.08 F/cm2 at 3 mA/cm2 and excellent rate capability of maintaining 61.69 % at 20 mA/cm2), which is superior to those of MnCo2O4.5, Co-Ni LDH and other metal oxides based composites reported. Meanwhile, the as-prepared hierarchical MnCo2O4.5@Co-Ni LDH electrode delivered improved electrical conductivity than that of pristine MnCo2O4.5. Furthermore, the as-constructed asymmetric supercapacitor using MnCo2O4.5@Co-Ni LDH as positive and activated carbon as negative electrode presented a rather high energy density of 220 μWh/cm2 at 2400 μW/cm2 and extraordinary cycling durability with the 100.0 % capacitance retention over 8000 cycles at 20 mA/cm2, demonstrating the best electrochemical performance compared to other asymmetric supercapacitors using metal oxides based composites as positive electrode material. It can be expected that the obtained MnCo2O4.5@Co-Ni LDH could be used as the high performance and cost-effective electrode in supercapacitors.


2018 ◽  
Vol 6 (4) ◽  
pp. 1802-1808 ◽  
Author(s):  
Ke Li ◽  
Yanshan Huang ◽  
Jingjing Liu ◽  
Mansoor Sarfraz ◽  
Phillips O. Agboola ◽  
...  

Three-dimensional graphene frameworks enable the development of stretchable asymmetric supercapacitors with a record high energy density of 77.8 W h kg−1, and also excellent stretchability and superior cycling stability.


2016 ◽  
Vol 4 (43) ◽  
pp. 16879-16885 ◽  
Author(s):  
Ya Wang ◽  
Hui Dou ◽  
Bing Ding ◽  
Jie Wang ◽  
Zhi Chang ◽  
...  

A symmetric capacitor based on facilely synthesized three-dimensional oriented porous carbon nanosheets delivers high energy density.


2020 ◽  
Vol 6 (21) ◽  
pp. eaay5098 ◽  
Author(s):  
Guangmin Zhou ◽  
Ankun Yang ◽  
Guoping Gao ◽  
Xiaoyun Yu ◽  
Jinwei Xu ◽  
...  

In lithium-sulfur (Li-S) chemistry, the electrically/ionically insulating nature of sulfur and Li2S leads to sluggish electron/ion transfer kinetics for sulfur species conversion. Sulfur and Li2S are recognized as solid at room temperature, and solid-liquid phase transitions are the limiting steps in Li-S batteries. Here, we visualize the distinct sulfur growth behaviors on Al, carbon, Ni current collectors and demonstrate that (i) liquid sulfur generated on Ni provides higher reversible capacity, faster kinetics, and better cycling life compared to solid sulfur; and (ii) Ni facilitates the phase transition (e.g., Li2S decomposition). Accordingly, light-weight, 3D Ni-based current collector is designed to control the deposition and catalytic conversion of sulfur species toward high-performance Li-S batteries. This work provides insights on the critical role of the current collector in determining the physical state of sulfur and elucidates the correlation between sulfur state and battery performance, which will advance electrode designs in high-energy Li-S batteries.


2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Lu Wang ◽  
Junwei Han ◽  
Debin Kong ◽  
Ying Tao ◽  
Quan-Hong Yang

Abstract Lithium-ion batteries (LIBs), which are high-energy-density and low-safety-risk secondary batteries, are underpinned to the rise in electrochemical energy storage devices that satisfy the urgent demands of the global energy storage market. With the aim of achieving high energy density and fast-charging performance, the exploitation of simple and low-cost approaches for the production of high capacity, high density, high mass loading, and kinetically ion-accessible electrodes that maximize charge storage and transport in LIBs, is a critical need. Toward the construction of high-performance electrodes, carbons are promisingly used in the enhanced roles of active materials, electrochemical reaction frameworks for high-capacity noncarbons, and lightweight current collectors. Here, we review recent advances in the carbon engineering of electrodes for excellent electrochemical performance and structural stability, which is enabled by assembled carbon architectures that guarantee sufficient charge delivery and volume fluctuation buffering inside the electrode during cycling. Some specific feasible assembly methods, synergism between structural design components of carbon assemblies, and electrochemical performance enhancement are highlighted. The precise design of carbon cages by the assembly of graphene units is potentially useful for the controlled preparation of high-capacity carbon-caged noncarbon anodes with volumetric capacities over 2100 mAh cm−3. Finally, insights are given on the prospects and challenges for designing carbon architectures for practical LIBs that simultaneously provide high energy densities (both gravimetric and volumetric) and high rate performance.


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