scholarly journals Diffraction studies of Tavorite-based polyanionic materials for Li–ion batteries

2014 ◽  
Vol 70 (a1) ◽  
pp. C356-C356
Author(s):  
Emmanuelle Suard ◽  
Matteo Bianchini ◽  
Jean-Marcel Ateba Mba ◽  
Christian Masquelier ◽  
Laurence Croguennec
Keyword(s):  
Phase Diagram ◽  
Low Voltage ◽  
Ex Situ ◽  
Li Ion Batteries ◽  
Two Phase ◽  
Whole Process ◽  
Structural Framework ◽  
Wide Range ◽  
Li Ion ◽  
Battery Discharge

Polyanionic materials attract great interest in the field of Li-ion batteries thanks to the wide range of possible available compositions, resulting in a great amount of different properties (1). For instance, the high working potential together with a capacity of 156 mAh/g (leading to a theoretical energy density of 655 Wh/g) made Tavorite LiVPO4F a widely studied material and a suitable candidate for commercial exploitation. Here we will focus our interest on the homeotype structure of LiVPO4O. This oxy-phosphate shows the ability to exploit two redox couples, V5+/V4+ at 3.95 V vs. Li+/Li and V4+/V3+ at an average potential of 2.3 V vs. Li+/Li upon Li+ extraction and insertion, respectively (2). The two domains show marked differences both in the electrochemical signature and in the phase diagram, which is extremely rich. In particular, while the high-voltage domain shows a relatively simple two-phase transformation between LiVPO4O and ε-VPO4O, the low-voltage domain is more complicated and it shows a series of three apparent biphasic reactions while Lithium is inserted in the Tavorite structural framework. To elucidate this reaction, we performed in-situ X-Ray diffraction (Kα1), i.e. we recorded the whole process in real time during battery discharge. The end member Li2VPO4O was also isolated ex-situ and its crystal structure determined for the first time thanks to neutron diffraction measurements (3). Both the phase diagram and the different crystal structures will be discussed.

scholarly journals Direct X-Ray Imaging as a Tool for Understanding Multiphysics Phenomena in Energy Storage

2016 ◽  
Vol 13 (3) ◽  
Author(s):  
George J. Nelson ◽  
Zachary K. van Zandt ◽  
Piyush D. Jibhakate
Keyword(s):  
Energy Storage ◽  
Lithium Ion ◽  
Ex Situ ◽  
Storage Device ◽  
Li Ion Batteries ◽  
X Ray ◽  
X Ray Imaging ◽  
Wide Range ◽  
Li Ion ◽  
Insight Into

The lithium-ion battery (LIB) has emerged as a key energy storage device for a wide range of applications, from consumer electronics to transportation. While LIBs have made key advancements in these areas, limitations remain for Li-ion batteries with respect to affordability, performance, and reliability. These challenges have encouraged the exploration for more advanced materials and novel chemistries to mitigate these limitations. The continued development of Li-ion and other advanced batteries is an inherently multiscale problem that couples electrochemistry, transport phenomena, mechanics, microstructural morphology, and device architecture. Observing the internal structure of batteries, both ex situ and during operation, provides a critical capability for further advancement of energy storage technology. X-ray imaging has been implemented to provide further insight into the mechanisms governing Li-ion batteries through several 2D and 3D techniques. Ex situ imaging has yielded microstructural data from both anode and cathode materials, providing insight into mesoscale structure and composition. Furthermore, since X-ray imaging is a nondestructive process studies have been conducted in situ and in operando to observe the mechanisms of operation as they occur. Data obtained with these methods has also been integrated into multiphysics models to predict and analyze electrode behavior. The following paper provides a brief review of X-ray imaging work related to Li-ion batteries and the opportunities these methods provide for the direct observation and analysis of the multiphysics behavior of battery materials.

scholarly journals Study on the structural phase transitions in NaSICON-type compounds using Ag3Sc2(PO4)3 as a model system

2020 ◽  
Vol 77 (1) ◽  
Author(s):  
Günther J. Redhammer ◽  
Gerold Tippelt ◽  
Quirin Stahl ◽  
Artur Benisek ◽  
Daniel Rettenwander
Keyword(s):  
Phase Transitions ◽  
Structural Phase ◽  
Ionic Conductivities ◽  
Phase Behaviour ◽  
Li Ion Batteries ◽  
Two Phase ◽  
Structured Materials ◽  
Β Phase ◽  
Nasicon Type ◽  
Li Ion

NaSICON (Na Super-Ionic CONducting) structured materials are among the most promising solid electrolytes for Li-ion batteries and `beyond Li-ion' batteries (e.g. Na and K) due to their superior ionic conductivities. Although this material has been well known for decades, its exact phase behaviour is still poorly understood. Herein, a starting material of Na3Sc2(PO4)3 single crystals is used, grown by flux methodology, where Na is subsequently chemically replaced by Ag, in order to take advantage of the higher scattering contrast of Ag. It is found that the NaSICON-type compound shows two phase transitions from a low-temperature monoclinic α-phase to a monoclinic β-phase at about 180 K and to a rhombohedral γ-phase at about 290 K. The framework of [Sc2(PO4)3]3− is rigid and does not change significantly with temperature and change of symmetry. The main driving force for the phase transitions is related to order–disorder phenomena of the conducting cations. The sensitivity of the phase behaviour on the ordering of these ions suggests that small compositional changes can have a great impact on the phase behaviour and, hence, on the ionic conductivity of NaSICON-structured materials.

Porous Al/Al2O3 two-phase nanonetwork to improve electrochemical properties of porous C/SiO2 as anode for Li-ion batteries

2019 ◽  
Vol 300 ◽  
pp. 470-481 ◽  
Author(s):  
Jinlong Cui ◽  
Jiachao Yang ◽  
Jianzong Man ◽  
Shaohui Li ◽  
Jinpeng Yin ◽  
...  
Keyword(s):  
Electrochemical Properties ◽  
Li Ion Batteries ◽  
Two Phase ◽  
Li Ion

Phase stability of Li–Mn–O oxides as cathode materials for Li-ion batteries: insights from ab initio calculations

2014 ◽  
Vol 16 (23) ◽  
pp. 11233-11242 ◽  
Author(s):  
R. C. Longo ◽  
F. T. Kong ◽  
Santosh KC ◽  
M. S. Park ◽  
J. Yoon ◽  
...  
Keyword(s):  
Phase Diagram ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Phase Stability ◽  
Cathode Materials ◽  
Chemical Potential ◽  
Li Ion Batteries ◽  
Li Ion ◽  
O Phase

The Li–Mn–O phase diagram as a function of the chemical potential of Li and O and the pH.

scholarly journals Pushing the limit of layered transition metal oxide cathodes for high-energy density rechargeable Li ion batteries

2018 ◽  
Vol 11 (5) ◽  
pp. 1271-1279 ◽  
Author(s):  
U.-H. Kim ◽  
D.-W. Jun ◽  
K.-J. Park ◽  
Q. Zhang ◽  
P. Kaghazchi ◽  
...  
Keyword(s):  
Thermal Stability ◽  
High Energy ◽  
High Energy Density ◽  
Li Ion Batteries ◽  
Two Phase ◽  
Oxide Cathodes ◽  
Li Ion ◽  
Layered Transition Metal ◽  
Thermal Stability Of ◽  
W Doping

W-doping produced the two-phase (Fm3̄m and R3̄m) structure which improved the cycling and thermal stability of the Ni-rich layered cathodes.

Synthesis and investigation of layered GeS as a promising large capacity anode with low voltage and high efficiency in full-cell Li-ion batteries

2017 ◽  
Vol 1 (8) ◽  
pp. 1607-1614 ◽  
Author(s):  
Yaqing Wei ◽  
Jun He ◽  
Qing Zhang ◽  
Chang Liu ◽  
Ameng Wang ◽  
...  
Keyword(s):  
High Efficiency ◽  
Low Voltage ◽  
Coulombic Efficiency ◽  
Cell Voltage ◽  
Li Ion Batteries ◽  
High Cell ◽  
Lithium Storage ◽  
Large Capacity ◽  
Full Cell ◽  
Li Ion

Layered GeS shows a large capacity of 1768 mA h g−1 with a coulombic efficiency of 94% for lithium storage. With good stability and a low voltage in alloying region, the LiCoO2//GeS full cell exhibits both high cell voltage and large capacity.

scholarly journals Electrochemical and electron microscopic characterization of Super-P based cathodes for Li–O2 batteries

2013 ◽  
Vol 4 ◽  
pp. 665-670 ◽  
Author(s):  
Mario Marinaro ◽  
Santhana K Eswara Moorthy ◽  
Jörg Bernhard ◽  
Ludwig Jörissen ◽  
Margret Wohlfahrt-Mehrens ◽  
...  
Keyword(s):  
Lithium Salt ◽  
Electrochemical Impedance ◽  
Ex Situ ◽  
Cathode Side ◽  
Li Ion Batteries ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
X Ray ◽  
Li Ion

Aprotic rechargeable Li–O2 batteries are currently receiving considerable interest because they can possibly offer significantly higher energy densities than conventional Li-ion batteries. The electrochemical behavior of Li–O2 batteries containing bis(trifluoromethane)sulfonimide lithium salt (LiTFSI)/tetraglyme electrolyte were investigated by galvanostatic cycling and electrochemical impedance spectroscopy measurements. Ex-situ X-ray diffraction and scanning electron microscopy were used to evaluate the formation/dissolution of Li2O2 particles at the cathode side during the operation of Li–O2 cells.

Direct evidence of a conversion mechanism in a NiSnO3 anode for lithium ion battery application

RSC Advances ◽  
2014 ◽  
Vol 4 (68) ◽  
pp. 36301-36306 ◽  
Author(s):  
Lijun Fu ◽  
Kepeng Song ◽  
Xifei Li ◽  
Peter A. van Aken ◽  
Chunlei Wang ◽  
...  
Keyword(s):  
Lithium Ion Battery ◽  
Matrix Function ◽  
Direct Evidence ◽  
Lithium Ion ◽  
The Self ◽  
Ex Situ ◽  
Li Ion Batteries ◽  
Li Ion ◽  
Battery Application

The ‘self-matrix’ function of NiSnO3 as an anode in Li-ion batteries has been investigated via ex situ TEM and SAED.

scholarly journals Resolving chemical and spatial heterogeneities at complex electrochemical interfaces in Li ion batteries

2021 ◽  
Author(s):  
Julia Hestenes ◽  
Richard May ◽  
Jerzy Sadowski ◽  
Naiara Munich ◽  
Lauren Marbella
Keyword(s):  
Spatial Information ◽  
Porous Electrode ◽  
Ex Situ ◽  
Solution Nmr ◽  
Material Surface ◽  
Crystallographic Structure ◽  
Li Ion Batteries ◽  
Composite Surface ◽  
Li Ion

The high specific capacities of Ni-rich transition metal oxides have garnered immense interest for improving the energy density of Li-ion batteries (LIBs). Despite the potential of these materials, Ni-rich cathodes suffer from interfacial instabilities that lead to crystallographic rearrangement of the active material surface as well as the formation of a cathode electrolyte interphase (CEI) layer on the composite during electrochemical cycling. While changes in crystallographic structure can be detected with diffraction-based methods, probing the chemistry of the disordered, heterogeneous CEI layer is challenging. In this work, we use a combination of ex situ solid-state nuclear magnetic resonance (SSNMR) spectroscopy and X-ray photoemission electron microscopy (XPEEM) to provide chemical and spatial information on the CEI deposited on LiNi0.8Mn0.1Co0.1O2 (NMC811) composite cathode films. Specifically, XPEEM elemental maps offer insight into the lateral arrangement of the electrolyte decomposition products that comprise the CEI and paramagnetic interactions (assessed with electron paramagnetic resonance (EPR) and relaxation measurements) in 13C SSNMR provide information on the radial arrangement of the CEI from the NMC811 particles outward. Using this approach, we find that LiF, Li2CO3, and carboxy-containing structures are directly appended to NMC811 active particles, whereas soluble species detected during in situ 1H and 19F solution NMR experiments (e.g., alkyl carbonates, HF, and vinyl compounds) are randomly deposited on the composite surface. We show that the combined approach of ex situ SSNMR and XPEEM, in conjunction with in situ solution NMR, allows spatially-resolved, molecular-level characterization of paramagnetic surfaces and new insights into electrolyte oxidation mechanisms in porous electrode films.

scholarly journals Operando Monitoring the Insulator-Metal Transition of LiCoO2

2021 ◽  
Author(s):  
Eibar Flores ◽  
Nataliia Mozhzhukhina ◽  
Ulrich Aschauer ◽  
Erik Berg
Keyword(s):  
Phase Transition ◽  
Solid Solution ◽  
Raman Spectroscopy ◽  
Dft Calculations ◽  
Active Material ◽  
Rate Capability ◽  
Li Ion Batteries ◽  
Two Phase ◽  
Insulator Metal Transition ◽  
Li Ion

LiCoO<sub>2</sub> (LCO) is one of the most-widely used cathode active materials for Li-ion batteries. Even though the material undergoes an electronic two-phase transition upon Li-ion cell charging, LCO exhibits competitive performance in terms of rate capability. Herein the insulator-metal transition of LCO is investigated by <i>operando</i> Raman spectroscopy complemented with DFT calculations and a newly-developed sampling volume model. We confirm the presence of a Mott insulator α-phase at dilute Li-vacancy concentrations (x > 0.87) that transforms into a metallic β-phase at x < 0.75. In addition, we find that the charge-discharge intensity trends of LCO Raman-active bands exhibit a characteristic hysteresis, which, unexpectedly, narrows at higher cycling rates. When comparing these trends to a newly-developed numerical model of laser penetration into a spatially-heterogeneous particle we provide compelling evidence that the insulator-metal transition of LCO follows a two-phase route at very low cycling rates, which is suppressed in favor of a solid-solution route at rates above 10 mA/g<sub>LCO</sub> (~C/10). The observations explain why LCO exhibits competitive rate capabilities despite being observed to undergo an intuitively slow two-phase transition route: a kinetically faster solid-solution transition route becomes available when the active material is cycled at rates >C/10. <i>Operando</i> Raman spectroscopy combined with sample volume modelling and DFT calculations is shown to provide unique insights into fundamental processes governing the performance of state-of-the-art cathode materials for Li-ion batteries.

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