Ionic/Electronic Conducting Characteristics of LiFePO[sub 4] Cathode Materials

Wang, Chunsheng; Hong, Junyoung

doi:10.1149/1.2409768

Cited by 233 publications

(151 citation statements)

References 23 publications

Supporting

Mentioning

146

Contrasting

Unclassified

Order By: Relevance

“…These properties ensure excellent rate capabilities, stable cycling and a long cycle life (Singh et al, 2013b). Previous measurements on another high rate material, LiFePO 4 (Wang and Hong, 2007), revealed that at high currents, 20C, and larger , ionic conduction in the electrolyte is the limiting factor as indicated by the enormous differences in concentration and local current near the electrolyte compared to the current collector. Similar limitations may be expected to arise in LTO electrodes at comparable C-rates and particle sizes .…”

Section: Resultsmentioning

confidence: 98%

“…Electrode porosity is a crucial electrode parameter as it strongly influences battery performance (Fongy et al, 2010a,b;Strobridge et al, 2015;Just, 2016;Liu et al, 2017). Generally, a larger porosity favors Li-ion transport allowing larger (dis)charge (Singh et al, 2013b;Just, 2016) at the expense of the volumetric density Singh et al, 2016) and electrical conductivity of the electrode (Wang and Hong, 2007;Fongy et al, 2010a). The optimum seems to be reached by a certain porosity gradient (Du et al, 2017;Liu et al, 2017).…”

Section: Resultsmentioning

confidence: 99%

“…A table containing stopping powers as a function of particle energy is obtained (Wang and Hong, 2007;Zhang et al, 2015;Liu and Co, 2016; using the open software package SRIM (Ziegler et al, 2010). Electrons associated in a molecular bond are delocalized and have significantly different binding energies.…”

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Operando Neutron Depth Profiling to Determine the Spatial Distribution of Li in Li-ion Batteries

Verhallen

Wagemaker

2018

Front. Energy Res.

View full text Add to dashboard Cite

Neutron Depth Profiling (NDP) allows determination of the spatial distribution of specific isotopes, via neutron capture reactions. In a capture reaction charged particles with fixed kinetic energy are formed, where their energy loss through the material of interest can be used to provide the depth of the original isotope. As lithium-6 has a relatively large probability for such a capture reaction, it can be used by battery scientists to study the lithium concentration in the electrodes even during battery operation. The selective measurement of the 6 Li isotope makes it a direct and sensitive technique, whereas the penetrative character of the neutrons allows practical battery pouch cells to be studied. Using NDP lithium diffusion and reaction rates can be studied operando as a function of depth, opening a large range of opportunities including the study of alloying reactions, metal plating, and (de) intercalation in insertion hosts. In the study of high rate cycling of intercalation materials the relatively low Li density challenges counting statistics while the limited change in electrode density due to the Li-ion insertion and extraction allows straightforward determination of the Li density as a function of electrode depth. If an electrode can be (dis)charged reversibly, data can be acquired and accumulated over multiple cycles to increase the time resolution. For Li metal plating and alloying reactions, the large lithium density allows good time resolution, however the large change of the electrode composition and density makes extracting the Li-density as a function of depth more challenging. Here an effective method is presented, using calibration measurements of the individual components, based on which the ratio of the components as a function of depth can be determined as well as the total Li-density. The same principles can be applied to insertion host materials, where the differences in density due to electrolyte infiltration yield the electrode porosity as a function of depth. This is of particular importance for battery electrodes where porosity has a direct influence on the energy density and charge transport.

show abstract

Section: Resultsmentioning

confidence: 98%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Operando Neutron Depth Profiling to Determine the Spatial Distribution of Li in Li-ion Batteries

Verhallen

Wagemaker

2018

Front. Energy Res.

View full text Add to dashboard Cite

show abstract

“…Recently, many studies on lithium iron phosphate have been published, mainly focused on the understanding and improvement of lithium-ion conduction in the active material (10)(11)(12). However, there are more physico-chemical processes which reduce the performance of LiFePO 4 -cells (13).…”

Section: Introductionmentioning

confidence: 99%

Evaluation of the Rate Determining Processes for LiFePO₄ as Cathode Material in Lithium-Ion-Batteries

et al. 2011

View full text Add to dashboard Cite

Lithium iron phosphate is a promising cathode material for the use in lithium-ion batteries meeting the demands of good stability during cycling and safe operation due to reduced risk of thermal runaway. However, slow solid state diffusion and poor electrical conductivity reduce power capability. For further improvement, all rate determining electrode processes have to be quantified. Electrochemical impedance spectroscopy (EIS) has proven to be a powerful tool for the characterization of electrochemical systems. In recent publications (1,2), a physical interpretation for the impedance response of LiFePO 4 /Li-cells was given and an equivalent circuit model was proposed. In this contribution, the proposed equivalent circuit is used to quantify the predominant electrode processes depending on temperature (0°C…30°C), SoC (10% … 100%) and microstructure characteristics (porosity).

show abstract

“…The decrease as much as possible of the size of the particles has two effects; first, it increases the effective electrode-electrolyte contact that is the active interface for electrochemical reactions, secondly, it reduces the pathway for electrons and lithium ions inside the bulk. Consequently, the electronic and ionic conductivity are small [40], this reduction is expected to be beneficial to the performance, especially at high C-rates. The experimental results, however, are not as simple as one might have expected because the reduction in size implies that surface effects become more important, and the surface layer does not necessarily have the same properties as the bulk, which impacts the electrochemical properties.…”

Section: Olivine-like Materialsmentioning

confidence: 99%

Nanotechnology of Positive Electrodes for Li-Ion Batteries

et al. 2017

View full text Add to dashboard Cite

Abstract:This work presents the recent progress in nanostructured materials used as positive electrodes in Li-ion batteries (LIBs). Three classes of host lattices for lithium insertion are considered: transition-metal oxides V 2 O 5 , α-NaV 2 O 5 , α-MnO 2 , olivine-like LiFePO 4 , and layered compounds LiNi 0.55 Co 0.45 O 2 , LiNi 1/3 Mn 1/3 Co 1/3 O 2 and Li 2 MnO 3 . First, a brief description of the preparation methods shows the advantage of a green process, i.e., environmentally friendliness wet chemistry, in which the synthesis route using single and mixed chelators is used. The impact of nanostructure and nano-morphology of cathode material on their electrochemical performance is investigated to determine the synthesis conditions to obtain the best electrochemical performance of LIBs.

show abstract

Ionic/Electronic Conducting Characteristics of LiFePO[sub 4] Cathode Materials

Cited by 233 publications

References 23 publications

Operando Neutron Depth Profiling to Determine the Spatial Distribution of Li in Li-ion Batteries

Operando Neutron Depth Profiling to Determine the Spatial Distribution of Li in Li-ion Batteries

Evaluation of the Rate Determining Processes for LiFePO₄ as Cathode Material in Lithium-Ion-Batteries

Nanotechnology of Positive Electrodes for Li-Ion Batteries

Contact Info

Product

Resources

About

Ionic/Electronic Conducting Characteristics of LiFePO[sub 4] Cathode Materials

Cited by 233 publications

References 23 publications

Operando Neutron Depth Profiling to Determine the Spatial Distribution of Li in Li-ion Batteries

Operando Neutron Depth Profiling to Determine the Spatial Distribution of Li in Li-ion Batteries

Evaluation of the Rate Determining Processes for LiFePO4 as Cathode Material in Lithium-Ion-Batteries

Nanotechnology of Positive Electrodes for Li-Ion Batteries

Contact Info

Product

Resources

About

Evaluation of the Rate Determining Processes for LiFePO₄ as Cathode Material in Lithium-Ion-Batteries