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All sourcesNASA NTRSDOE OSTI
DOE OSTI2026

Garnet/PVDF-HFP Hybrid Membranes for Li-Metal Batteries: Cooperative Research and Development Final Report, CRADA Number CRD-19-00807

Hazen Research, Inc., in collaboration with University of Colorado, Boulder (CU-B) and National Renewable Energy Laboratory (NREL), will develop and demonstrate a ceramic-polymer hybrid membrane based on garnet (Li7La3Zr2O12) and PVDF (Poly Vinylidene Fluoride)-HFP (Hexafluoropropylene) adaptable to Li-metal anodes. Under this CRADA, NREL will test the developed membranes providing feedback and advice to demonstrate hybrid membranes with Li-ion conductivity >10-4 S/cm at room temperature that are stable with Li-metal, followed by demonstration of full cells with Li-metal anode.

33 ADVANCED PROPULSION SYSTEMS↗
NASA NTRS1992

Symposium on High Power, Ambient Temperature Lithium Batteries, 180th Meeting of the Electrochemical Society, Phoenix, AZ, Oct. 13-17, 1991, Proceedings

Papers presented in these proceedings are on the state of the art in high-power lithium batteries, a design analysis of high-power Li-TiS2 battery, the performance and safety features of spiral wound lithium/thionyl chloride cells, the feasibility of a superhigh energy density battery of the Li/BrF3 electrochemical system, and an enhanced redox process of disulfide compounds and their application in high energy storage. Attention is also given to the structure and charge-discharge characteristics of mesophase-pitch based carbons, a study of carbons and graphites as anodes for lithium rechargeable cells, Li metal-free rechargeable Li(1+x)Mn2O4/carbon cells, and rechargeable lithium batteries using V6O13/V5O5 as the positive electrode material. Other papers discuss the electrochemical stability of organic electrolytes in contact with solid inorganic cathode materials, the electrochemical behavior of methyl formate solutions, and the interface between a solid polymer electrolyte and lithium anode.

Clark, W. D. K.↗
DOE OSTI2020

Highly-Cyclable Room-Temperature Phosphorene Polymer Electrolyte Composites for Li Metal Batteries

Despite significant interest toward solid-state electrolytes owing to their superior safety in comparison to liquid-based electrolytes, sluggish ion diffusion and high interfacial resistance limit their application in durable and high-power density batteries. Here, a novel quasi-solid Li + ion conductive nanocomposite polymer electrolyte containing black phosphorous (BP) nanosheets is reported. The developed electrolyte is successfully cycled against Li metal (over 550 h cycling) at 1 mA cm -2 at room temperature. The cycling overpotential is dropped by 75% in comparison to BP-free polymer composite electrolyte indicating lower interfacial resistance at the electrode/electrolyte interfaces. Molecular dynamics simulations reveal that the coordination number of Li + ions around (trifluoromethanesulfonyl)imide (TFSI - ) pairs and ethylene-oxide chains decreases at the Li metal/electrolyte interface, which facilitates the Li + transport through the polymer host. Here, density functional theory calculations confirm that the adsorption of the LiTFSI molecules at the BP surface leads to the weakening of N and Li atomic bonding and enhances the dissociation of Li + ions. This work offers a new potential mechanism to tune the bulk and interfacial ionic conductivity of solid-state electrolytes that may lead to a new generation of lithium polymer batteries with high ionic conduction kinetics and stable long-life cycling.

2D materials↗
DOE OSTI2020

Impact of Ionic Liquid on Lithium Ion Battery with a Solid Poly(Ionic Liquid) Pentablock Terpolymer as Electrolyte and Separator

In this work, a ternary blend solid polymer electrolyte (SPE) consisting of a poly(ionic liquid) (PIL) multiblock polymer, lithium salt, and ionic liquid (IL) was investigated with the goal of understanding the influence of IL concentration on ion transport mechanisms and electrochemical stability. The physical, transport, mechanical, morphological, and electrochemical properties of the ternary blend SPE were systematically investigated as a function of IL concentration (r = [IL]/[PIL] mole ratio between 0.1 and 0.7). The results indicate that with increasing IL concentration, the continuous conductive domain increases along with the polymer chain segmental mobility, as well as facilitate ionic conductivity, while the mechanical modulus exhibits a percolation threshold (from 52.17 MPa to 0.55 MPa at r = 0.2 to 0.3). Surprisingly, at higher IL concentrations, there is a reduction in the lithium cation mobility (i.e., 9.3 × 10-12 m2 s-1 versus 3.8 × 10-12 m2 s-1 for r = 0.2 versus r = 0.5, respectively) as evidenced by pulsed-field gradient nuclear magnetic resonance (PFG-NMR), which coincides with an increased overpotential (i.e., 50 mV versus 150 mV for r = 0.2 versus r = 0.5, respectively) evidenced by lithium metal stripping and plating. This work provides valuable insights into the impact of IL on lithium ion conducting PIL block polymers, which may enable the design of new SPEs with both high ionic conductivity and improved stability for the future lithium ion batteries.

Chen, Tzu-Ling↗
DOE OSTI2023

Highly Conductive Polyoxanorbornene‐Based Polymer Electrolyte for Lithium‐Metal Batteries

Abstract This present study illustrates the synthesis and preparation of polyoxanorbornene‐based bottlebrush polymers with poly(ethylene oxide) (PEO) side chains by ring‐opening metathesis polymerization for solid polymer electrolytes (SPE). In addition to the conductive PEO side chains, the polyoxanorbornene backbones may act as another ion conductor to further promote Li‐ion movement within the SPE matrix. These results suggest that these bottlebrush polymer electrolytes provide impressively high ionic conductivity of 7.12 × 10 −4 S cm −1 at room temperature and excellent electrochemical performance, including high‐rate capabilities and cycling stability when paired with a Li metal anode and a LiFePO 4 cathode. The new design paradigm, which has dual ionic conductive pathways, provides an unexplored avenue for inventing new SPEs and emphasizes the importance of molecular engineering to develop highly stable and conductive polymer electrolytes for lithium‐metal batteries (LMB).

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Review of Emerging Potassium–Sulfur Batteries

Abstract This is the first review on potassium–sulfur (K–S) batteries (KSBs), which are emerging metal battery (MB) systems. Since KSBs are quite new, there are fundamental questions regarding the electrochemistry of S‐based cathode and of K metal anode, as well as the holistic aspects of full‐cell performance. The manuscript begins with a critical discussion regarding the potassium–sulfur electrochemistry and on how it differs from the much better‐known lithium–sulfur. Cathodes are discussed next, focusing on the role of sulfur structure, carbon host chemistry and porosity, and electrolytes in establishing the reversible potassium sulfide K 2 S n phase sequence, the parasitic polysulfide shuttle, pulverization‐driven capacity fade, etc. Following is a discussion of solid‐state electrolytes (SSEs), including of hybrid solid–liquid systems that show much promise. Potassium metal anodes are then critically reviewed, emphasizing electrolyte reactions to form stable versus unstable solid electrolyte interphase (SEI), covering the current understanding of potassium dendrites, and highlighting the deep‐eutectic K–Na alloying approaches for room temperature liquid anodes. The manuscript concludes with K–S batteries, focusing on cell architectures and providing quantitative performance comparisons as master plots. Unanswered scientific/technological questions are identified, emerging research opportunities are discussed, and potential experimental and simulation‐based studies that can unravel these unknowns are proposed.

Ding, Jia↗
NASA NTRS1994

The JPL Direct Methanol Liquid-feed PEM Fuel Cell

Recently, there has been a breakthrough in fuel cell technology in the Energy Storage Systems Group at the Jet Propulsion Laboratory with the develpment of a direct methanol, liquid-feed, solid polymer electrolyte membrane (PEM) fuel cell... The methanol liquid-feed, solid polymer electrolyte (PEM) design has numerous system level advantages over the gas-feed design. These include:...

fuel cells methanol pem methanol water↗
DOE OSTI2023

Degradation of Lithium Iron Phosphate Sulfide Solid-State Batteries by Conductive Interfaces

The superionic solid-state argyrodite electrolyte Li 6 PS 5 Br can improve lithium and lithium-ion batteries' safety and energy density. Despite many reports validating the conductivity of this electrolyte, it still suffers from passivating electrode degradation mechanisms. At first analysis, lithium iron phosphate (LFP) should be more thermodynamically stable in contact with sulfide electrolytes. However, without substantial improvements to interfacial engineering, we find that LFP is not inherently stable against Li 6 PS 5 Br. We hypothesize argyrodite oxidation favorably competes with LFPAs delithiation, insulating the electrolyte-electrode interface and causing large overpotential losses. We show that compared to LiNi x Mn y Co z O 2 , LFP has no actual electrochemical stability advantage despite operating at a lower voltage. We utilize tender energy XAS and XPS to show that chemical reactions occur between LFP and the Li 6 PS 5 Br solid electrolyte and these reactions are exacerbated by cycling. We also show that electrochemical degradation occurs at the interface between the solid electrolyte ion conductor and any electron conductor, namely the active material and carbon additives. We further demonstrate that LiNbO 3 cathode coatings on LFP can delay electrochemical degradation by electronically insulating the LFP-sulfide electrolyte interface but not prevent its occurrence at the carbon-electrolyte interface.

25 ENERGY STORAGE↗
DOE OSTI2024

Low Melting Temperature Gallium–Indium Liquid Metal Anode for Solid-State Li-Ion Batteries

Solid-state Li-ion batteries are attracting attention for their enhanced safety features, higher energy density, and broader operational temperature range compared to systems based on liquid electrolytes. However, current solid-state Li-ion batteries face performance challenges, such as suboptimal cycling and poor rate capabilities, often due to inadequate interfacial contact between the solid electrolyte and electrodes. To address this issue, we incorporated a gallium–indium (Ga–In) liquid metal as the anode in a solid-state Li-ion battery setup, employing Li 6 PS 5 Cl as the solid electrolyte. Operating at room temperature, this configuration achieved an initial capacity of 389 mAh g –1 and maintained 88% of this capacity after 30 cycles at a 0.05 C rate. It also demonstrated a capacity retention of 66% after 500 cycles at a 0.5 C rate. In comparison to solid anode materials, such as tin, the Ga–In liquid metal exhibited superior cycling stability and rate capacity, which is due to the self-healing and fluid properties of the alloy that ensure stable interfacial contact with solid electrolytes. In situ X-ray diffraction (XRD) and ex situ scanning electron microscope (SEM) analyses revealed that indium does not directly participate in the lithiation/delithiation process. Instead, it helps maintain the alloy’s low melting point, facilitating its return to a liquid state after delithiation. In a comparative analysis of stack pressure during cycling in cells utilizing Ga–In liquid metal and tin, the Ga–In liquid metal cell demonstrated an ability to buffer pressure increases associated with deformation. In conclusion, these findings suggest a promising approach for enhancing solid-state batteries by integrating liquid metal anodes, which improve interfacial contact and stability.

Alloys↗
DOE OSTI2022

Evaluation of steam supply performance: Steamer vs. bubbler

Water/steam electrolysis is a key enabling technology for clean, low-carbon and sustainable production of hydrogen and will play a crucial role in future hydrogen economy. For high temperature solid oxide electrolytic cells, steam is the chemical feedstock. A stable and accurate supply of steam to solid oxide electrolytic cells is of vital importance to smooth production of hydrogen. In this study, we compare steam supply performance of two commonly used steam generators: steamer and bubbler. Our results show that bubbler with proper volume and fritted inlet gas tubing can provide more stable and accurate steam supply than steamer for laboratory use. We also provide the explanation for the unstable steam supply observed in steamer. Overall, we conclude that bubbler is generally a better choice for small-scale laboratory use (e.g., ≤50%H 2 O, ≤100 sccm carrier gas flow) to produce stable and accurate steam and steamer might be a better choice for higher steam contents and flow rates (e.g., >60% H 2 O and >200) encountered in large-scale testing and/or aggressive high steam conditions.

08 HYDROGEN↗
DOE OSTI2024

Factors Affecting the Electron Conductivity in Single Crystal Li 7 La 3 Zr 2 O 12 and Li 7 P 3 S 11

One of the serious challenges in all solid-state Li ion batteries is neutral Li intrusion into the solid-state electrolyte that can ultimately cause catastrophic failure. One possibility for this is due to n-type electron conductivity that induces the reaction Li + + e – → Li 0 at sites where the potential is less than the Li + /Li potential. This paper reports hybrid density functional theory calculations of the electronic conductivity in two prototype single crystalline solid-state electrolytes, cubic Li 7 La 3 Zr 2 O 12 (c-LLZO) and Li 7 P 3 S 11 (LPS). The formation energies of important point defects that can affect electron conductivity are determined, and we find that the mechanism of n-type electron conductivity for both solid-state electrolytes is via “small” electron polaron hopping, where the quotes signify that substantial Li ion rearrangement is associated with the polaron formation and its migration. In both electrolytes, the formation energies for the small polarons at the Fermi energy are too high to generate measurable electron conductivity at room temperature. For c-LLZO, the concentration of electron polarons necessary to ensure charge neutrality from positively charged oxygen vacancies formed in synthesis can be significantly higher. Hence, the electron conductivity could be significant when measured with ion-blocking metal electrodes, and we discuss how the synthesis conditions could affect this magnitude. However, in the solid-state battery, these polarons are replaced by negatively charged Li vacancies so that the electron conductivity should remain minimal. For LPS single crystals, the inherent minimal electron conductivity is independent of synthesis conditions. Here we also show that the cost of forming Li 0 in bulk c-LLZO is enormous due to strain effects so that it could only potentially form at voids, grain boundaries, or around vacancy defects which relax the lattice strain.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Polymer-ceramic composite electrolytes for all-solid-state lithium batteries: Ionic conductivity and chemical interaction enhanced by oxygen vacancy in ceramic nanofibers

Perovskite Li 3x La 2/3-x TiO3 (LLTO) nanofibers have been heat-treated in the hydrogen-containing atmosphere and then incorporated with the poly(vinylidene fluoride)-co-hexafluoropropylene (PVDF-HFP) polymer to form a composite electrolyte. Hydrogen treatment has created oxygen vacancies in the LLTO nanofibers, which has reduced the activation energy of Li ion transport along intra-grains and inter-grains, leading to improvement in the ion conductivity of LLTO nanofibers. Hydrogen treatment of the LLTO nanofibers has also enhanced the chemical interaction between the LLTO nanofibers and the polymer matrix in the composite electrolyte, and favored the Li ion transport at the nanofiber/polymer interface, improving the ion conductivity of the composite electrolyte to 3.4×10- 4 S/cm at room temperature. As a result, the Li|composite-electrolyte|Li half-cell exhibits good stability during lithium plating/stripping cycling at room temperature, showing an overpotential of ~91 mV at a constant current density of 0.5 mA/cm 2 . Finally, the full-cell battery with the composite electrolyte, lithium metal anode and lithium iron phosphate cathode shows excellent rate capacity and cycling performance.

25 ENERGY STORAGE↗
DOE OSTI2020

Nonuniform Ionic and Electronic Transport of Ceramic and Polymer/Ceramic Hybrid Electrolyte by Nanometer-Scale Operando Imaging for Solid-State Battery

Replacing the liquid electrolyte in lithium batteries with solid-state ion conductor is promising for next-generation energy storage that is safe and has high energy density. In this work, nanometer-resolution ionic and electronic transport imaging of Li 3 PS 4 (LPS), a solid-state electrolyte (SSE), is reported. This nm resolution is achieved by using a logarithm-scale current amplifier that enhances the current sensitivity to the fA range. Large fluctuations of ion current—one to two orders of magnitude on the LPS and on the LPS region of a polymer/LPS bulk hybrid SSE—that must be mitigated to eliminate Li dendrite formation and growth, are found. This ion current fluctuation is understood in terms of highly anisotropic transport kinetic barriers along the different crystalline axes due to different grain orientations in the polycrystalline and glass ceramic materials. The results on the bulk hybrid SSE show a sharp transition of ionic and electronic transport at the LPS/polymer boundary and decreases in average ionic current with decreasing polyimine particle size and with extensive cycling. The results elucidate the mechanism of polyimine extension into interparticles to prevent Li dendrite growth. This work opens up novel characterization of charge transport, which relates to Li plating and stripping for solid-state-batteries.

Li3PS4↗
DOE OSTI2022

Spatiotemporal mapping of microscopic strains and defects to reveal Li-dendrite-induced failure in all-solid-state batteries

Solid-state electrolytes (SSEs) are key to the success and reliability of all-solid-state lithium batteries, potentially enabling improvements in terms of safety and energy density over state-of-the-art lithium-ion batteries. However, there are several critical challenges to their implementation, including the interfacial instability stemming from the dynamic interaction of as-formed dendritic lithium during cycling. Here, we emphasize the importance of studying the spatial distribution and temporal evolution of strains and defects in crystalline solid-state electrolytes at the micro-scale, and how this affects dendrite growth. A proof-of-principle study is demonstrated using the synchrotron radiation based micro Laue X-ray diffraction method, and a custom-developed in-situ cycling device. Defects and residual strains are mapped, and the evolution of intragranular misorientation is observed. The feasibility of using this technique is discussed, and recommendations for micro-strain engineering to address the Li/SSEs interfacial issues are given. Additionally, work directions are pointed out with the consideration of combining multi-techniques for “poly-therapy”.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Halide Substitution Effects on Lithium-Ion Diffusion in Protonated Antiperovskites

Solid-state electrolytes (SSEs) for all-solid-state lithium-ion batteries are generating intense interest because these batteries can improve the safety and performance compared with devices fabricated with conventional, flammable liquid electrolytes. In these SSEs, it has been suggested that Li + ion diffusion in the grain boundaries is hindered and is a critical determinant of the overall ionic conductivity (σ). However, Li + ion diffusivities in the grain (D G ) and the grain boundary (D GB ) are difficult to determine experimentally, with few techniques capable of distinguishing the individual contributions. Here, we distinguished the D G and D GB for the protonated lithium antiperovskites (pLiAPs) SSEs: Li 2 OHCl, Li 2 OHBr, Li 2 OHF 0.1 Cl 0.9 , Li 2 OHF 0.1 Br 0.9 , and Li 2 OHCl 0.3 7Br 0.63 . The measurements were obtained directly from 7 Li pulsed-field gradient nuclear magnetic resonance (PFG-NMR) at 353 K. The 7 Li PFG-NMR echo profiles were composed of two primary components with additional secondary oscillatory components – the so-called NMR diffraction phenomenon. The length scale separating the two main components corresponds to a diffusion length of ~1.7 µm, which is thought to be the average grain size (by diameter). The short-range (≤ 1.7 µm) diffusion component associated with D G (≈10 -11 m 2 /s) varied minimally with halide substitution, while the long-range (≥ 1.7 µm) component D GB (≈10 -12 to 10 -15 m 2 /s) was highly sensitive to the substitution of halides and closely correlated with s. In addition, from the comparison of the ratio D GB /D G to D t (the Li + ion diffusion coefficient estimated from the rotational correlation time, t c ), it was determined that the contribution of D G to σ is negligible; 0.01 ~ 0.04 in the pLiAPs studied here. Finally, these insights provide fundamental understanding of the halide substitution effects on Li + ion grain versus grain boundary diffusion, and suggest that careful engineering of the grain boundaries at the microscopic level is necessary to achieve high-performance pLiAP SSEs.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

STRUCTURE AND PROPERTIES STUDY ON ENERGY MATERIALS: THERMOELECTRIC MATERIAL TETRAHEDRITE AND LITHIUM ION CONDUCTOR

Development of efficient energy materials is critical in order to ease the energy demand and reduce our dependence of fossil fuel. Thermoelectric materials are promising due to their capability of generating electrical power by recovering waste heat. The performance of thermoelectric materials is quantified by a dimensionless figure of merit zT, which depends on their properties such as electrical conductivity, Seebeck coefficient and thermal conductivity. Tetrahedrites, a copper antimony sulfosalt mineral, typified by Cu 12-x MxSb 4 S 13 , where M is a transition metal element such as Ni, Zn, Fe or Mn, have great potential for thermoelectric application due to their relatively high zT (close to 1 at 700 K), earth-abundance, environmental friendliness, favorable electrical properties, and most importantly intrinsic low lattice thermal conductivity (less than 1 W m -1 K -1 ) in wide temperature. In addition to energy recovery, reliable energy storage devices are also emerging to relieve the energy demand and improve the efficiency of consuming energy resources. Lithium-ion batteries are known to be reliable and successful electrochemical energy storage devices and appliable in various aspects, including laptops, smartphones and electrical vehicles. Lithium phosphorous oxynitride (LiPON) are widely used as thin-film solid-state electrolytes in Li-ion battery, which is the only demonstrated solid-state electrolyte that is quite stable in direct contact with Li metal at potentials from 0-5 V. However, the structure of LiPON, the effects of N doping, and the origin of its good electrochemical stability remains inconclusive. In this thesis, reliable modeling techniques accompanied with experimental tools, are applied to study the thermoelectric material tetrahedrite and the ionic conductor LiPON, in order to study their structural and dynamical properties. Accurate and efficient density-functional theory (DFT) and density-functional tight-binding (DFTB) methods, combined with molecular dynamics (MD) simulations are utilized in order to investigate the structures and properties of these energy materials. The incoherent and coherent atomic dynamics study of tetrahedrite Cu 10.5 NiZn 0.5 Sb 4 S 13 provides the origin of softening upon cooling by investigate the motion of Cu12e at different temperatures. The dynamic structure factors in the longitudinal and transverse direction will also be discussed. The Cu movement of Cu-rich tetrahedrite Cu 14 Sb 4 S 13 is revealed by Cu self-diffusivity, nuclear density map and “nudged elastic band” (NEB). Moreover, we investigate the effect of simulation cell size and basis sets on the DFT-based MD simulation results using tetrahedrite Cu1 0 Zn 2 Sb 4 S 13 thermoelectric as a model material, showing the advantage of larger cell by accessing smaller Q range. In addition, the low-temperature structural properties of Cu 12 Sb 4 S 13 is measured by neutron diffraction, which indicates that no cubic to tetragonal transition occurs at metal-semiconductor transition (MST) temperature. Thermoelectric properties such as Seebeck coefficient, electrical resistivity and electrical thermal conductivity will also be investigated. DFTB method is implemented to study the structure and transport properties of Li 3 PO 4 and LiPON, while the exploration of N doping effect is included. Lastly, the LiPON/Li interphase will be revealed in order to study the origin of electrochemical stability.

Li, Junchao↗
DOE OSTI2020

STRUCTURE AND PROPERTIES STUDY ON ENERGY MATERIALS: THERMOELECTRIC MATERIAL TETRAHEDRITE AND LITHIUM ION CONDUCTOR LiPON

Development of efficient energy materials is critical in order to ease the energy demand and reduce our dependence of fossil fuel. Thermoelectric materials are promising due to their capability of generating electrical power by recovering waste heat. The performance of thermoelectric materials is quantified by a dimensionless figure of merit zT, which depends on their properties such as electrical conductivity, Seebeck coefficient and thermal conductivity. Tetrahedrites, a copper antimony sulfosalt mineral, typified by Cu12-xMxSb4S13, where M is a transition metal element such as Ni, Zn, Fe or Mn, have great potential for thermoelectric application due to their relatively high zT (close to 1 at 700 K), earth-abundance, environmental friendliness, favorable electrical properties, and most importantly intrinsic low lattice thermal conductivity (less than 1 W m-1 K-1) in wide temperature. In addition to energy recovery, reliable energy storage devices are also emerging to relieve the energy demand and improve the efficiency of consuming energy resources. Lithium-ion batteries are known to be reliable and successful electrochemical energy storage devices and appliable in various aspects, including laptops, smartphones and electrical vehicles. Lithium phosphorous oxynitride (LiPON) are widely used as thin-film solid-state electrolytes in Li-ion battery, which is the only demonstrated solid-state electrolyte that is quite stable in direct contact with Li metal at potentials from 0-5 V. However, the structure of LiPON, the effects of N doping, and the origin of its good electrochemical stability remains inconclusive.In this thesis, reliable modeling techniques accompanied with experimental tools, are applied to study the thermoelectric material tetrahedrite and the ionic conductor LiPON, in order to study their structural and dynamical properties. Accurate and efficient density-functional theory (DFT) and density-functional tight-binding (DFTB) methods, combined with molecular dynamics (MD) simulations are utilized in order to investigate the structures and properties of these energy materials. The incoherent and coherent atomic dynamics study of tetrahedrite Cu10.5NiZn0.5Sb4S13 provides the origin of softening upon cooling by investigate the motion of Cu12e at different temperatures. The dynamic structure factors in the longitudinal and transverse direction will also be discussed. The Cu movement of Cu-rich tetrahedrite Cu14Sb4S13 is revealed by Cu self-diffusivity, nuclear density map and "nudged elastic band" (NEB). Moreover, we investigate the effect of simulation cell size and basis sets on the DFT-based MD simulation results using tetrahedrite Cu10Zn2Sb4S13 thermoelectric as a model material, showing the advantage of larger cell by accessing smaller Q range. In addition, the low-temperature structural properties of Cu12Sb4S13 is measured by neutron diffraction, which indicates that no cubic to tetragonal transition occurs at metal-semiconductor transition (MST) temperature. Thermoelectric properties such as Seebeck coefficient, electrical resistivity and electrical thermal conductivity will also be investigated. DFTB method is implemented to study the structure and transport properties of Li3PO4 and LiPON, while the exploration of N doping effect is included. Lastly, the LiPON/Li interphase will be revealed in order to study the origin of electrochemical stability

25 ENERGY STORAGE↗