scholarly journals Surface Modified Pinecone Shaped Hierarchical Structure Fluorinated Mesocarbon Microbeads for Ultrafast Discharge and Improved Electrochemical Performances

2016 ◽  
Vol 164 (2) ◽  
pp. A1-A7 ◽  
Author(s):  
Yang Dai ◽  
Yuan Fang ◽  
Sendan Cai ◽  
Lijun Wu ◽  
Weijing Yang ◽  
...  
Keyword(s):  
Hierarchical Structure ◽  
Electrochemical Performances ◽  
Mesocarbon Microbeads ◽  
Surface Modified

Enhancement of Lithium Battery Performance by Thickness Anode Film Modification

2015 ◽  
Vol 827 ◽  
pp. 156-161
Author(s):  
Rani Cahyani Fajaryatun ◽  
Therecia Wulan Sukardi ◽  
Arif Jumari ◽  
Agus Purwanto
Keyword(s):  
Polyvinylidene Fluoride ◽  
Lithium Battery ◽  
Lithium Iron Phosphate ◽  
Iron Phosphate ◽  
Electrochemical Performances ◽  
X Ray Diffraction ◽  
Battery Voltage ◽  
X Ray ◽  
Mesocarbon Microbeads ◽  
Anode Film

A lithium battery was composed of anode, cathode, and separator. The performance of lithium battery was influenced by the thickness of film, the composition of material, and the effect of surfactant and binder. This research investigated the effect of the anode film thickness to the electrochemical performances of lithium battery. Mesocarbon microbeads (MCMB) and lithium iron phosphate (LiFePO4) were used respectively as anode and cathode. Mesocarbon microbeads, carbon black (conductive agent), polyvinylidene fluoride (PVDF) as a binder and N-methyl-2-pyrrolidone (NMP) as a solvent were mixed well to produce slurry. The slurry were then coated, dried and pressed. The anode had various thickness of 50 μm, 70 μm, 100 μm, and 150 μm. The cathode film was made with certain thickness. The performance of lithium battery was examined by Eight Channel Battery Analyzer, the composition of the anode sample was examined by XRD (X-Ray Diffraction), and the crystal structure of the anode sample was analyzed by SEM (Scanning Electron Microscope). The research showed that the thickness of anode film of 100 μm gave the best performance. The battery performance decreased if the thickness was more than 100 μm. The best performance of battery voltage were between 3649 mV and 3650 mV.

Enhanced Electrochemical Performances of LiFePO4/C Cathode Materials by Deposited with Ge Film

2014 ◽  
Vol 936 ◽  
pp. 480-485
Author(s):  
Yan Dan Huang ◽  
Ying Bin Lin ◽  
Zhi Gao Huang
Keyword(s):  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Active Material ◽  
Rate Capability ◽  
Film Surface ◽  
Charge Transfer Resistance ◽  
Electrochemical Performances ◽  
Cyclic Voltammograms ◽  
Transfer Resistance ◽  
Surface Modified

LiFePO4/C-Ge electrodes were prepared with vacuum thermal evaporation deposition by depositing Ge films on as-prepared LiFePO4/C electrodes. The effect of Ge film on the electrochemical performances of LiFePO4/C cells was investigated systematically by charge/discharge testing, cyclic voltammograms and AC impedance spectroscopy, respectively. It was found that Ge-film-surface modified LiFePO4/C showed excellent electrochemical performances compared to that of the pristine one in terms of cyclability and rate capability. At 60°C, LiFePO4/C-Ge film exhibited outstanding cyclability with less than 5% capacity fade after 50 cycles while the pristine one suffers 15%. Analysis from the electrochemical measurements showed that the presence of Ge film on the LiFePO4/C electrode would protect active material from HF generated by the decomposition of LiPF6 in the electrolyte and stabilize the surface structure of active material during the charge and discharge cycle. Electrochemical impedance spectroscopy (EIS) results indicated that Ge film mainly reduced the charge transfer resistance Rct of LiFePO4/C electrode, resulting from the suppression of the solid electrolyte interfacial (SEI) film.

scholarly journals Facile Synthesis of Multi-channel Surface Modified Amorphous Iron Oxide Nanospheres as a High-performance Anode Material for Lithium-ion Batteries

2021 ◽  
Author(s):  
Shijin Yu ◽  
Wenzhen Zhu ◽  
Zhuohao Xiao ◽  
Jiahao Tong ◽  
Quanya Wei ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Surface Structure ◽  
Lithium Ion Batteries ◽  
High Performance ◽  
Lithium Ion ◽  
Electrochemical Performances ◽  
Lithium Ions ◽  
Channel Surface ◽  
Voltage Hysteresis ◽  
Surface Modified

Abstract The application of iron oxide as anode of lithium-ion batteries is hindered by its poor cycle stability, low rate performance and large voltage hysteresis. To address these problems, multi-channel surface modified amorphous Fe2O3 nanospheres were synthesized by using a facile hydrothermal method, which exhibited outstanding electrochemical performances. According to crystalline state and microstructure, it was found that surface structure of the amorphous Fe2O3 nanospheres can be controlled by adjusting the reaction time, due to the synergistic effect of ripening and hydrogen ion etching. Owing to the isotropic nature and the absence of grain boundaries, the amorphous Fe2O3 nanospheres could withstand high strains during the intercalation of lithium ions. Meanwhile, the multi-channel surface structure can not only increase the contact area between Fe2O3 nanospheres and electrolyte, but also reserve space for volume expansion after lithium storage, thereby effectively alleviating the volume change during the intercalation-deintercalation of lithium ions. As confirmed by the Galvanostatic intermittent titration analysis results, the amorphous Fe2O3 electrode had higher Li+ diffusion coefficient than the crystalline counterpart. As a result, the multi-channel surface modified amorphous Fe2O3 electrode exhibited higher specific capacity, more stable cycle performance and narrower voltage hysteresis. It is believed that amorphous metal oxides have great potential as high-performance anode of next-generation lithium-ion batteries.

scholarly journals Application of PVDF Organic Particles Coating on Polyethylene Separator for Lithium Ion Batteries

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3125 ◽  
Author(s):  
Yuan Wang ◽  
Chuanqiang Yin ◽  
Zhenglin Song ◽  
Qiulin Wang ◽  
Yu Lan ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Polyvinylidene Fluoride ◽  
Retention Rate ◽  
Rate Capability ◽  
Lithium Ion ◽  
Organic Polymer ◽  
Electrochemical Performances ◽  
Capacity Retention ◽  
Organic Particles ◽  
Surface Modified

Surface coating modification on a polyethylene separator serves as a promising way to meet the high requirements of thermal dimensional stability and excellent electrolyte wettability for lithium ion batteries (LIBs). In this paper, we report a new type of surface modified separator by coating polyvinylidene fluoride (PVDF) organic particles on traditional microporous polyethylene (PE) separators. The PE separator coated by PVDF particles (PE-PVDF separator) has higher porosity (61.4%), better electrolyte wettability (the contact angle to water was 3.28° ± 0.21°) and superior ionic conductivity (1.53 mS/cm) compared with the bare PE separator (51.2%, 111.3° ± 0.12°, 0.55 mS/cm). On one hand, the PVDF organic polymer has excellent organic electrolyte compatibility. On the other hand, the PVDF particles contain sub-micro spheres, of which the separator can possess a large specific surface area to absorb additional electrolyte. As a result, LIBs assembled using the PE-PVDF separator showed better electrochemical performances. For example, the button cell using a PE-PVDF as the separator had a higher capacity retention rate (70.01% capacity retention after 200 cycles at 0.5 C) than the bare PE separator (62.5% capacity retention after 200 cycles at 0.5 C). Moreover, the rate capability of LIBs was greatly improved as well—especially at larger current densities such as 2 C and 5 C.

scholarly journals Graphene aerogel supported crystalline ZnO@amorphous Zn2GeO4 core–shell hierarchical structure for lithium storage

RSC Advances ◽  
2017 ◽  
Vol 7 (29) ◽  
pp. 17769-17772 ◽  
Author(s):  
Meng Jiang ◽  
Tengfei Zhou ◽  
Wei Liu ◽  
Chuanqi Feng ◽  
Jianwen Liu ◽  
...  
Keyword(s):  
Hierarchical Structure ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Core Shell ◽  
Electrochemical Performances ◽  
Graphene Aerogel ◽  
Lithium Storage ◽  
Three Dimensional Structure ◽  
Enhanced Stability

A crystalline–amorphous core–shell ZnO/Zn2GeO4/graphene aerogel with a three-dimensional structure has been successfully fabricated and shows enhanced stability and electrochemical performances.

Lithiophilic Sb Surface Modified Cu Nanowires Grown on Cu Foam: A Synergy of 1D@3D Hierarchical Structure toward Stable Lithium Metal Anodes

2021 ◽  
Author(s):  
Xuelian Fu ◽  
Chaoqun Shang ◽  
Guofu Zhou ◽  
Xin Wang
Keyword(s):  
Hierarchical Structure ◽  
Electrochemical Property ◽  
Dendrite Growth ◽  
Lithium Metal ◽  
Safety Risk ◽  
Cu Nanowires ◽  
Lithium Metal Anodes ◽  
Surface Modified ◽  
Cu Foam ◽  
Metal Anodes

The uncontrollable lithium (Li) dendrite growth during repeated cycles involves safety risk and undesirable electrochemical property of Li metal batteries (LMBs). This hinders the commercialization of LMBs. To realize dendrite-free...

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