scholarly journals Experimental and Modeling Analysis of Holey Graphene Electrodes for High-Power-Density Li-Ion Batteries

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1063
Author(s):  
Yu-Ren Huang ◽  
Cheng-Lung Chen ◽  
Nen-Wen Pu ◽  
Chia-Hung Wu ◽  
Yih-Ming Liu ◽  
...  
Keyword(s):  
Ion Transport ◽  
Ethylene Carbonate ◽  
Solid Electrolyte Interphase ◽  
Specific Capacity ◽  
Rate Capability ◽  
Lithium Ion ◽  
Md Simulations ◽  
Sei Layer ◽  
Uniform Dispersion ◽  
Li Ion

The performances of lithium-ion batteries (LIBs) using holey graphene (HGNS) as the anode material are compared with those using non-holey graphene (GNS). The effects of graphene holes on ion transport are analyzed with a combined experiment/modeling approach involving molecular dynamics (MD) simulations. The large aspect ratio of GNS leads to long transport paths for Li ions, and hence a poor rate capability. We demonstrate by both experiments and simulations that the holey structure can effectively improve the rate capability of LIBs by providing shortcuts for Li ion diffusion through the holes in fast charge/discharge processes. The HGNS anode exhibits a high specific capacity of 745 mAh/g at 0.1 A/g (after 80 cycles) and 141 mAh/g at a large current density of 10 A/g, which are higher than the capacity values of the GNS counterpart by 75% and 130%, respectively. MD simulations also reveal the difference in lithium ion transport between GNS and HGNS anodes. The calculations indicate that the HGNS system has a higher diffusion coefficient for lithium ions than the GNS system. In addition, it shows that the holey structure can improve the uniformity and quality of the solid electrolyte interphase (SEI) layer, which is important for Li ion conduction across this layer to access the electrode surface. Moreover, quantum chemistry (QC) computations show that ethylene carbonate (EC), a cyclic carbonate electrolyte with five-membered-ring molecules, has the lowest electron binding energy of 1.32 eV and is the most favorable for lithium-ion transport through the SEI layer. A holey structure facilitates uniform dispersion of EC on graphene sheets and thus enhances the Li ion transport kinetics.

scholarly journals A Non-Flammable Zwitterionic Ionic Liquid/Ethylene Carbonate Mixed Electrolyte for Lithium-Ion Battery with Enhanced Safety

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4225
Author(s):  
Zeliang Guan ◽  
Zhijun Zhang ◽  
Binyang Du ◽  
Zhangquan Peng
Keyword(s):  
Ionic Liquid ◽  
Ionic Conductivity ◽  
Safety Issue ◽  
Ethylene Carbonate ◽  
Specific Capacity ◽  
Rate Capability ◽  
Lithium Ion ◽  
Mixed Electrolyte ◽  
The Stability ◽  
Reliable Solution

Today, the requirement for clean, highly efficient, and safe energy seems to be higher and higher due to non-renewable energy and pollution of the environment. At this moment, lithium-ion batteries (LIBs) look like a reliable solution for this dilemma since they have huge energy density. However, the flammability of the conventional electrolyte used in the LIBs is one of critical disadvantages of LIBs, which compromises the safety issue of LIBs. Herein, we reported a non-flammable zwitterionic ionic liquid-based electrolyte named TLPEC, which was fabricated by simply mixing a novel zwitterionic ionic liquid TLP (93 wt%) and ethylene carbonate (EC, 7 wt%). The TLPEC electrolyte exhibited a wide electrochemical potential window of 1.65–5.10 V and a robust ionic conductivity of 1.0 × 10−3 S cm−1 at 20 °C, which renders TLPEC to be a suitable electrolyte for LIBs with enhanced safety performance. The LIBs, with TLPEC as the electrolyte, exhibited an excellent performance in terms of excellent rate capability, cycling stability, and high specific capacity at 25 and 60 °C, which were attributed to the stability and high ionic conductivity of TLPEC electrolyte during cycling as well as the excellent interface compatibility of TLPEC electrolyte with lithium anode.

The Effect of Solvent on the Capacity Retention in a Germanium Anode for Lithium Ion Batteries

2018 ◽  
Vol 15 (4) ◽  
Author(s):  
Kuber Mishra ◽  
Wu Xu ◽  
Mark H. Engelhard ◽  
Ruiguo Cao ◽  
Jie Xiao ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Photoelectron Spectroscopy ◽  
Ethylene Carbonate ◽  
Solid Electrolyte Interphase ◽  
Lithium Ion ◽  
Capacity Retention ◽  
Sei Layer ◽  
Capacity Degradation ◽  
Fluoroethylene Carbonate

A thin and mechanically stable solid electrolyte interphase (SEI) is desirable for a stable cyclic performance in a lithium ion battery. For the electrodes that undergo a large volume expansion, such as Si, Ge, and Sn, the presence of a robust SEI layer can improve the capacity retention. In this work, the role of solvent choice on the electrochemical performance of Ge electrode is presented by a systematic comparison of the SEI layers in ethylene carbonate (EC)-based and fluoroethylene carbonate (FEC)-based electrolytes. The results show that the presence of FEC as a cosolvent in a binary or ternary solvent electrolyte results in an excellent capacity retention of ∼85% after 200 cycles at the current density of 500 mA g−1; while EC-based electrode suffers a rapid capacity degradation with a capacity retention of just 17% at the end of 200 cycles. Post analysis by an extensive use of X-ray photoelectron spectroscopy (XPS) was carried out, which showed that the presence of Li2O in FEC-based SEIs was the origin for the improved electrochemical performance.

Rate Capability Testing of Graphite Electrode Material

2021 ◽  
Vol 105 (1) ◽  
pp. 43-51
Author(s):  
Jiri Libich ◽  
Josef Maca ◽  
Marie Sedlarikova ◽  
Antonín Šimek ◽  
Pavel Cudek ◽  
...  
Keyword(s):  
Lithium Ion Battery ◽  
Electrode Materials ◽  
Graphite Electrode ◽  
Solid Electrolyte Interphase ◽  
Rate Capability ◽  
Negative Electrode ◽  
Lithium Ion ◽  
Lithium Ions ◽  
Sei Layer ◽  
Process Formation

The paper deals with the investigation of natural graphite electrode materials for lithium-ion batteries. These negative electrode materials operate on the intercalation principle where graphite plays a host role for lithium ions. There is a solid electrolyte interphase (SEI) layer which origins from electrode-electrolyte interphase. The SEI layer is a fundamental part of lithium-ion battery system and its quality defines and highly affects the overall quality of lithium-ion battery itself. Growth of the SEI layer is connected with the formation of new compounds. The process formation of SEI layer is linked to energy consumption (energy loss). What is most important is the fact that the growth of SEI layer consumes the significant amount of lithium ions provided from a limited positive electrode (cathode) source. In this work, the lithiation method was employed to reduce these undesirable side effects of the SEI growth.

scholarly journals Progress in Preparation and Modification of LiNi0.6Mn0.2Co0.2O2 Cathode Material for High Energy Density Li-Ion Batteries

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Lipeng Xu ◽  
Fei Zhou ◽  
Bing Liu ◽  
Haobing Zhou ◽  
Qichang Zhang ◽  
...  
Keyword(s):  
Cathode Materials ◽  
Low Cost ◽  
Specific Capacity ◽  
Rate Capability ◽  
Lithium Ion ◽  
High Energy ◽  
High Energy Density ◽  
Synthesis Methods ◽  
High Specific Capacity ◽  
Li Ion

Due to the advantages of high specific capacity, various temperatures, and low cost, layered LiNi0.6Co0.2Mn0.2O2 has become one of the potential cathode materials for lithium-ion battery. However, its application was limited by the high cation mixing degree and poor electric conductivity. In this paper, the influences of synthesis methods and modification such surface coating and doping materials on the electrochemical properties such as capacity, cycle stability, rate capability, and impedance of LiNi0.6Co0.2Mn0.2O2 cathode materials are reviewed and discussed. The confronting issues of LiNi0.6Co0.2Mn0.2O2 cathode materials have been pointed out, and the future development of its application is also prospected.

scholarly journals A Commercial Carbonaceous Anode with a-Si Layers by Plasma Enhanced Chemical Vapor Deposition for Lithium Ion Batteries

2020 ◽  
Vol 4 (2) ◽  
pp. 72
Author(s):  
Chao-Yu Lee ◽  
Fa-Hsing Yeh ◽  
Ing-Song Yu
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Coulombic Efficiency ◽  
Low Cost ◽  
Specific Capacity ◽  
Rate Capability ◽  
Lithium Ion ◽  
Chemical Vapor ◽  
Li Ion Battery ◽  
Li Ion

In this study, we propose a mass production-able and low-cost method to fabricate the anodes of Li-ion battery. Carbonaceous anodes, integrated with thin amorphous silicon layers by plasma enhanced chemical vapor deposition, can improve the performance of specific capacity and coulombic efficiency for Li-ion battery. Three different thicknesses of a-Si layers (320, 640, and 960 nm), less than 0.1 wt% of anode electrode, were deposited on carbonaceous electrodes at low temperature 200 °C. Around 30 mg of a-Si by plasma enhanced chemical vapor deposition (PECVD) can improve the specific capacity ~42%, and keep coulombic efficiency of the half Li-ion cells higher than 85% after first cycle charge-discharge test. For the thirty cyclic performance and rate capability, capacitance retention can maintain above 96%. The thicker a-Si layers on carbon anodes, the better electrochemical performance of anodes with silicon-carbon composites we get. The traditional carbonaceous electrodes can be deposited a-Si layers easily by plasma enhanced chemical vapor deposition, which is a method with high potential for industrialization.

scholarly journals Effect of FSI Based Ionic Liquid on High Voltage Li-Ion Batteries

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2879
Author(s):  
Wenlin Zhang ◽  
Yongqi Zhao ◽  
Yu Huo
Keyword(s):  
Ionic Liquid ◽  
Molecular Orbital ◽  
High Voltage ◽  
Electrode Materials ◽  
Ethylene Carbonate ◽  
Solid Electrolyte Interphase ◽  
Specific Capacity ◽  
Lithium Ion ◽  
Voltage Range ◽  
Discharge Specific Capacity

In this manuscript, a functionalized ionic liquid 1-cyanoethyl-2-methyl-3-allylimidazolium bis (trifluoromethanesulfonimide) salt (CEMAImTFSI) was synthesized and explored as an electrolyte component to improve the oxidation resistance of the electrolyte in high-voltage lithium-ion batteries. Based on the calculation by Gaussian 09, CEMAImTFSI has a higher highest occupied molecular orbital (HOMO) value than the organic solvents ethylene carbonate (EC) and dimethyl carbonate (DMC), suggesting that CEMAImTFSI is more susceptible to oxidation than EC and DMC. Moreover, a low Li+ binding energy value of –3.71 eV and the lower lowest unoccupied molecular orbital (LUMO) enable CEMAImTFSI to migrate easily to the surface of the LiNi0.5Mn1.5O4 cathode and participate in the formation of the SEI (solid electrolyte interphase) film, protecting the electrode materials. Electrochemical studies showed that the LiNi0.5Mn1.5O4/Li cell with 1.0 mol/L LiPF6-EC/DMC/10 vol% has the best cycling stability in the voltage range of 3–5 V. The initial discharge specific capacity of the cells was 131.03 mAh·g−1 at 0.2 C, and even after 50 cycles the discharge specific capacity value of 126.06 mAhg−1 was observed, with the cell showing a capacity retention as high as 96.2%. Even at the rate of 5 C, the average discharge specific capacity of the cell was still 109.30 mAh·g−1, which was 1.95 times higher than the cell without the CEMAImTFSI addition. The ionic liquid molecules adsorption on the cell electrode surface was confirmed by X-ray photoelectron spectroscopic (XPS) analysis after charge–discharge measurements.

scholarly journals Incorporation of redox-active polyimide binder into LiFePO4 cathode for high-rate electrochemical energy storage

2020 ◽  
Vol 9 (1) ◽  
pp. 1350-1358
Author(s):  
Qing Zhang ◽  
Zongfeng Sha ◽  
Xun Cui ◽  
Shengqiang Qiu ◽  
Chengen He ◽  
...  
Keyword(s):  
Polyvinylidene Fluoride ◽  
Specific Capacity ◽  
Rate Capability ◽  
Lithium Ion ◽  
High Energy ◽  
High Rate ◽  
High Energy Density ◽  
Redox Active ◽  
Uniform Dispersion ◽  
Lifepo4 Cathode

Abstract Commercial LiFePO4 (LFP) electrode still cannot meet the demand of high energy density lithium-ion batteries as a result of its low theoretical specific capacity (170 mA h g−1). Instead of traditional electrochemical inert polyvinylidene fluoride (PVDF), the incorporation of multifunctional polymeric binder becomes a possible strategy to overcome the bottleneck of LFP cathode. Herein, a novel polyimide (PI) binder was synthesized through a facile hydrothermal polymerization route. The PI binder exhibits better connection between active particles with uniform dispersion than that of PVDF. The multifunctional PI binder not only shows well dispersion stability in the organic electrolyte, but also contributes to extra capacity because of the existence of electrochemical active carbonyl groups in the polymer chain. Besides, the high intrinsic ion conductivity of PI also results in promoted ion transfer kinetic. Consequently, the LFP cathode using PI binder (LFP–PI) shows larger capacity and better rate capability than LFP cathode with PVDF binder (LFP–PVDF). Meanwhile, the superior binding ability also endows LFP–PI with great cycling stability compared to the LFP–PVDF electrode.

Rational design of Sn-based multicomponent anodes for high performance lithium-ion batteries: SnO2@TiO2@reduced graphene oxide nanotubes

RSC Advances ◽  
2016 ◽  
Vol 6 (4) ◽  
pp. 2920-2925 ◽  
Author(s):  
Jun Young Cheong ◽  
Chanhoon Kim ◽  
Ji Soo Jang ◽  
Il-Doo Kim
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
High Performance ◽  
Rational Design ◽  
Solid Electrolyte Interphase ◽  
Rate Capability ◽  
Lithium Ion ◽  
Sei Layer ◽  
Reduced Graphene ◽  
Coated Layer

Reduced graphene oxide (rGO)-wrapped SnO2@TiO2 nanotubes (NTs) anodes exhibit superior rate capability and cycle retention due to stable solid electrolyte interphase (SEI) layer and enhanced electrical conductivity through TiO2 and rGO-coated layer.

Hierarchically porous nitrogen-rich carbon derived from wheat straw as an ultra-high-rate anode for lithium ion batteries

2014 ◽  
Vol 2 (25) ◽  
pp. 9684-9690 ◽  
Author(s):  
Li Chen ◽  
Yongzhi Zhang ◽  
Chaohong Lin ◽  
Wen Yang ◽  
Yan Meng ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Wheat Straw ◽  
Specific Capacity ◽  
Rate Capability ◽  
Lithium Ion ◽  
High Rate ◽  
Li Ion Battery ◽  
Hierarchically Porous ◽  
Li Ion ◽  
Battery Anode

Hierarchically porous nitrogen-rich carbon derived from wheat straw presents an impressive specific capacity and ultrahigh rate capability as a Li-ion battery anode.

Sign in / Sign up

Export Citation Format

Share Document