milerssliu/battery-device-data-qa huggingface dataset:
As seen from the surface morphology images of these three electrodes (Fig. 2 and S5†), they have their own characteristics and are all totally different from the original IF (Fig. S6†). As shown in Fig. 2a, there are abundant FeCO3 cubes (8–15 μm in edge length) on the surface of the FeCO3@IF electrode. The TEM images (Fig. 2b) show that the width of the crystal lattice is about 0.278 nm, matching the (104) face of FeCO3, which confirms the formation of FeCO3 and coincides with the results in the XRD patterns and XPS spectra. According to the SEM images in Fig. 2a, S5a and b,† the FeCO3 cubes do not completely cover the surface of the IF. As shown in Fig. 2c, the surface of the area without FeCO3 cubes is rough and is clearly different from the smooth surface of IF (Fig. S6†). According to the distribution of elements (C, O and Fe) in the area without FeCO3 cubes, C, O and Fe are uniformly distributed (Fig. S7b–d†). The EDS data (Fig. S7e†) confirm that the C, O and Fe content (wt%) is 8.63%, 35.58% and 55.79%, respectively. Therefore, the atomic ratio of C, O and Fe is 1.00:3.09:1.38, which is close to the atomic ratio of FeCO3. The slightly high iron content may be due to the iron foam substrate. These results confirm that the area without FeCO3 cubes is also covered by FeCO3 compounds. In addition, the TEM results in Fig. 2 further show that aside from the FeCO3 cubes with high crystallinity according to their long-range ordered crystal structure (Fig. 2b), some compounds with short-range ordered and long-range disordered crystal structures are also observed (Fig. 2d). The widths of the crystal lattices are about 0.278 nm and 0.234 nm, which match the (104) and (110) faces of FeCO3, respectively. Therefore, the compounds on the surface of IF without FeCO3 cubes are mainly FeCO3 but with low crystallinity according to the EDS and TEM results. Unlike FeCO3@IF, Fe3O4@IF is covered with tightly packed Fe3O4 nanoparticles (Fig. 2c, S5c and d†). The morphology of Fe–O–M@IF is similar to that of FeCO3@IF, but many long and interlaced nanowires are distributed around the cubes. Moreover, the edge length of the cubes is 2–3 times that of FeCO3@IF, and the surface is uneven. Compared with the original IF with its smooth surface, the increase in roughness can improve the specific surface area (Fig. S8 and Table S2†) and promote the penetration of the electrolyte as well as mass transfer. Based on the above characterizations, three different 3D iron-based electrodes have been successfully prepared via changing the iron source.

Question: What's the electrolyte?
Herein, we fabricated two artificial SEIs on Na metal anodes via similar chemical replacement reactions between Na metal and SnCl4 liquid or SnCl2 additive dissolved in diethylene glycol dimethyl ether (DGM). According to X-ray photoelectron spectroscopy (XPS) depth-profiling results, the SnCl4 liquid treatment leads to a uniform and high ionic diffusion artificial SEI consisting of a simultaneously generated Na–Sn alloy and NaCl, whereas the SnCl2 additive results in a disordered and heterogeneous artificial SEI (Na–Sn alloy, NaCl, Sn metal, organo-chloride, ROCO2Na and RCH2ONa) due to the heterogeneous reaction between the Na metal anode and SnCl2/DGM solvent. It is found that the cycling performance of the SnCl4–Na electrodes is highly superior to that of the SnCl2–Na electrodes, which is mainly ascribed to the uniformity and ionic diffusion distinction of the two artificial SEIs. The importance of homogeneous and high ionic diffusion properties for the artificial SEI is also demonstrated by simulation results. Overall, the artificial SEI of SnCl4–Na electrodes can afford three key advantages: (i) the simple and controllable fabrication leads to a homogeneous artificial SEI consisting of uniformly distributed Na–Sn alloy and NaCl, avoiding the non-uniform products caused by the side reactions that commonly exist in electrolyte additive methods; (ii) both Na–Sn alloy and NaCl possess much higher diffusion coefficients than organic components (ROCO2Na and RCH2ONa) and conventional SEIs, enabling fast ion diffusion and restraining the initiation of Na dendrites; (iii) the high Young's moduli of the Na–Sn alloy and NaCl can also help suppress the growth of Na dendrites. With the above excellent properties, the SnCl4–Na electrode provides an ultralong cycling stability with a stable voltage polarization (∼100 mV) for 4000 h with a cycling capacity of 3 mA h cm−2 at 2 mA cm−2. Moreover, the SnCl4–Na electrode also shows excellent cycling stability for ∼1500 h even under rather tough conditions (5 mA h cm−2, 5 mA cm−2). In addition, benefiting from the durable SEI layer, a SnCl4–Na|FeS2 full cell can deliver a stable capacity of ∼350 mA h g−1 for 380 cycles.

Question: What's the anode?
Answer: Na metal
Herein, we fabricated two artificial SEIs on Na metal anodes via similar chemical replacement reactions between Na metal and SnCl4 liquid or SnCl2 additive dissolved in diethylene glycol dimethyl ether (DGM). According to X-ray photoelectron spectroscopy (XPS) depth-profiling results, the SnCl4 liquid treatment leads to a uniform and high ionic diffusion artificial SEI consisting of a simultaneously generated Na–Sn alloy and NaCl, whereas the SnCl2 additive results in a disordered and heterogeneous artificial SEI (Na–Sn alloy, NaCl, Sn metal, organo-chloride, ROCO2Na and RCH2ONa) due to the heterogeneous reaction between the Na metal anode and SnCl2/DGM solvent. It is found that the cycling performance of the SnCl4–Na electrodes is highly superior to that of the SnCl2–Na electrodes, which is mainly ascribed to the uniformity and ionic diffusion distinction of the two artificial SEIs. The importance of homogeneous and high ionic diffusion properties for the artificial SEI is also demonstrated by simulation results. Overall, the artificial SEI of SnCl4–Na electrodes can afford three key advantages: (i) the simple and controllable fabrication leads to a homogeneous artificial SEI consisting of uniformly distributed Na–Sn alloy and NaCl, avoiding the non-uniform products caused by the side reactions that commonly exist in electrolyte additive methods; (ii) both Na–Sn alloy and NaCl possess much higher diffusion coefficients than organic components (ROCO2Na and RCH2ONa) and conventional SEIs, enabling fast ion diffusion and restraining the initiation of Na dendrites; (iii) the high Young's moduli of the Na–Sn alloy and NaCl can also help suppress the growth of Na dendrites. With the above excellent properties, the SnCl4–Na electrode provides an ultralong cycling stability with a stable voltage polarization (∼100 mV) for 4000 h with a cycling capacity of 3 mA h cm−2 at 2 mA cm−2. Moreover, the SnCl4–Na electrode also shows excellent cycling stability for ∼1500 h even under rather tough conditions (5 mA h cm−2, 5 mA cm−2). In addition, benefiting from the durable SEI layer, a SnCl4–Na|FeS2 full cell can deliver a stable capacity of ∼350 mA h g−1 for 380 cycles.

Question: What's the electrolyte?
In this work, we carry out classical reactive molecular dynamics (MD) simulations for studying the initial formation of SEI films occurring by Li oxidation and simultaneous decomposition of electrolyte (salt and solvent) molecules in the liquid phase in contact with the Li-metal electrode. We use lithium hexafluorophosphate (LiPF6) as a salt because its reductive decomposition has been pointed as critical on the SEI formation and lithium trifluoromethanesulfonate (lithium triflate or LiTF) that has shown interesting performance in various systems. We study the behavior of the various system components (i.e. Li-metal anode slab, and salt and solvent molecules) when the electrolyte solution is put in contact with the Li metal surface. We follow the evolution of various events including the lithium metal expansion/dissolution, salt and solvent decomposition, and initial nucleation of the SEI intermediates and products as well as the electron exchange among the species. We aim to identify the effects of electrolyte composition on the Li-metal anode behavior and the SEI formation and growth at open circuit conditions. We focus only on the initial stages of SEI formation, concentrated in a specific part of the battery system, and do not examine the Li deposition events occurring when an ionic flux arrives at the anode during charge, and the effects of an applied field. To gain further understanding of the structures and mechanisms of the initial stages of SEI formation, density functional theory (DFT) calculations on initial Li–F were used to evaluate SEI fragments observed in MD simulations. Once optimized structures of such fragments are obtained, we investigated the fragment clustering processes found at initial stages of SEI nucleation. These simulations provide preliminary estimations for the energies of formation and clustering of LiF fragments.

Question: What's the anode?
Answer: Li-metal
In this work, we carry out classical reactive molecular dynamics (MD) simulations for studying the initial formation of SEI films occurring by Li oxidation and simultaneous decomposition of electrolyte (salt and solvent) molecules in the liquid phase in contact with the Li-metal electrode. We use lithium hexafluorophosphate (LiPF6) as a salt because its reductive decomposition has been pointed as critical on the SEI formation and lithium trifluoromethanesulfonate (lithium triflate or LiTF) that has shown interesting performance in various systems. We study the behavior of the various system components (i.e. Li-metal anode slab, and salt and solvent molecules) when the electrolyte solution is put in contact with the Li metal surface. We follow the evolution of various events including the lithium metal expansion/dissolution, salt and solvent decomposition, and initial nucleation of the SEI intermediates and products as well as the electron exchange among the species. We aim to identify the effects of electrolyte composition on the Li-metal anode behavior and the SEI formation and growth at open circuit conditions. We focus only on the initial stages of SEI formation, concentrated in a specific part of the battery system, and do not examine the Li deposition events occurring when an ionic flux arrives at the anode during charge, and the effects of an applied field. To gain further understanding of the structures and mechanisms of the initial stages of SEI formation, density functional theory (DFT) calculations on initial Li–F were used to evaluate SEI fragments observed in MD simulations. Once optimized structures of such fragments are obtained, we investigated the fragment clustering processes found at initial stages of SEI nucleation. These simulations provide preliminary estimations for the energies of formation and clustering of LiF fragments.

Question: What's the electrolyte?
In this work, we carry out classical reactive molecular dynamics (MD) simulations for studying the initial formation of SEI films occurring by Li oxidation and simultaneous decomposition of electrolyte (salt and solvent) molecules in the liquid phase in contact with the Li-metal electrode. We use lithium hexafluorophosphate (LiPF6) as a salt because its reductive decomposition has been pointed as critical on the SEI formation and lithium trifluoromethanesulfonate (lithium triflate or LiTF) that has shown interesting performance in various systems. We study the behavior of the various system components (i.e. Li-metal anode slab, and salt and solvent molecules) when the electrolyte solution is put in contact with the Li metal surface. We follow the evolution of various events including the lithium metal expansion/dissolution, salt and solvent decomposition, and initial nucleation of the SEI intermediates and products as well as the electron exchange among the species. We aim to identify the effects of electrolyte composition on the Li-metal anode behavior and the SEI formation and growth at open circuit conditions. We focus only on the initial stages of SEI formation, concentrated in a specific part of the battery system, and do not examine the Li deposition events occurring when an ionic flux arrives at the anode during charge, and the effects of an applied field. To gain further understanding of the structures and mechanisms of the initial stages of SEI formation, density functional theory (DFT) calculations on initial Li–F were used to evaluate SEI fragments observed in MD simulations. Once optimized structures of such fragments are obtained, we investigated the fragment clustering processes found at initial stages of SEI nucleation. These simulations provide preliminary estimations for the energies of formation and clustering of LiF fragments.

Question: What's the anode?
Answer:  Li-metal
Driven by the urgent demand for electrical energy storage in electric vehicles, rechargeable devices with high energy densities and long cycle life continue to attract great interest. Lithium-ion batteries (LIBs) have attracted increasing attention over the past few decades owing to many merits, including high energy density, no memory effect, and good safety. However, making further improvements in their energy density whilst maintaining high safety remains highly challenging, inhibiting the scale-up of their applications. Developing new electrode materials is one of the most efficient ways to achieve LIBs with high energy and high safety. Silicon (Si) is considered to be a promising replacement for the graphite anodes in conventional LIBs, due to its ultrahigh specific capacity (4200 mA h g−1, ten times that of graphite), low working potential (ca. 0.4 V versus Li+/Li), natural abundance, high safety and environmentally benign nature. Unfortunately, Si has a low intrinsic electronic conductivity and this restricts charge transfer within Si anodes during the charge–discharge process. Moreover, the large volume change (>300%) of the Si anode during the lithiation/delithiation process leads to drastic particle pulverization and uncontrollable growth of a solid electrolyte interphase (SEI), leading to electrical contact loss between the active materials themselves or the active materials and current collectors. All these inherent problems lead to Si anodes having poor rate performance, low coulombic efficiency (CE) and fast capacity decay on cycling.

Question: What's the anode?
Answer: graphite
Driven by the urgent demand for electrical energy storage in electric vehicles, rechargeable devices with high energy densities and long cycle life continue to attract great interest. Lithium-ion batteries (LIBs) have attracted increasing attention over the past few decades owing to many merits, including high energy density, no memory effect, and good safety. However, making further improvements in their energy density whilst maintaining high safety remains highly challenging, inhibiting the scale-up of their applications. Developing new electrode materials is one of the most efficient ways to achieve LIBs with high energy and high safety. Silicon (Si) is considered to be a promising replacement for the graphite anodes in conventional LIBs, due to its ultrahigh specific capacity (4200 mA h g−1, ten times that of graphite), low working potential (ca. 0.4 V versus Li+/Li), natural abundance, high safety and environmentally benign nature. Unfortunately, Si has a low intrinsic electronic conductivity and this restricts charge transfer within Si anodes during the charge–discharge process. Moreover, the large volume change (>300%) of the Si anode during the lithiation/delithiation process leads to drastic particle pulverization and uncontrollable growth of a solid electrolyte interphase (SEI), leading to electrical contact loss between the active materials themselves or the active materials and current collectors. All these inherent problems lead to Si anodes having poor rate performance, low coulombic efficiency (CE) and fast capacity decay on cycling.

Question: What's the electrolyte?
Driven by the urgent demand for electrical energy storage in electric vehicles, rechargeable devices with high energy densities and long cycle life continue to attract great interest. Lithium-ion batteries (LIBs) have attracted increasing attention over the past few decades owing to many merits, including high energy density, no memory effect, and good safety. However, making further improvements in their energy density whilst maintaining high safety remains highly challenging, inhibiting the scale-up of their applications. Developing new electrode materials is one of the most efficient ways to achieve LIBs with high energy and high safety. Silicon (Si) is considered to be a promising replacement for the graphite anodes in conventional LIBs, due to its ultrahigh specific capacity (4200 mA h g−1, ten times that of graphite), low working potential (ca. 0.4 V versus Li+/Li), natural abundance, high safety and environmentally benign nature. Unfortunately, Si has a low intrinsic electronic conductivity and this restricts charge transfer within Si anodes during the charge–discharge process. Moreover, the large volume change (>300%) of the Si anode during the lithiation/delithiation process leads to drastic particle pulverization and uncontrollable growth of a solid electrolyte interphase (SEI), leading to electrical contact loss between the active materials themselves or the active materials and current collectors. All these inherent problems lead to Si anodes having poor rate performance, low coulombic efficiency (CE) and fast capacity decay on cycling.

Question: What's the anode?
Answer: Si
All electrochemical measurements were carried out on a CHI 660E electrochemical workstation. The electrochemical properties of the prepared electrodes were tested using a three-electrode system in 1 M H2SO4 aqueous electrolyte. A platinum plate and a saturated calomel electrode (SCE) served as the counter electrode and the reference electrode, respectively. N-PCNFAs and PCNFAs sandwiched tightly between two pieces of 304 stainless steel meshes were directly used as the binder/additive-free working electrodes held by a clamp. To investigate the electrochemical properties, cyclic voltammetry (CV), galvanostatic charge–discharge (GCD) and electrochemical impedance spectroscopy (EIS, a frequency response analysis over the frequency range from 100 kHz to 10 mHz) were carried out. The specific capacitance of the electrode material was calculated from discharge curves according to the following equation (eqn (1)): where Cm is the specific capacitance (F g−1), I is the constant discharge current (A), Δt is the discharge time (s), m is the total mass of the active material (g) and ΔV is the set potential window (V).

Question: What's the electrolyte?
Answer: 1 M H2SO4 aqueous
Semiconducting polymers swell in typical organic solvents allowing ion penetration and high transconductance. However, for biosensing applications it is essential to operate in aqueous environments. Due to the non-polar nature of polymers, this limits their ability to swell and thus limits performance in aqueous media. A biphasic electrolyte platform developed by Duong et al. incorporates two immiscible electrolytes, an organic layer in direct contact with the polymer and aqueous layer on top. The former is selected because it allows ion penetration into P3HT so it can operate as an OECT, whilst the less dense aqueous layer interfaces with the biological environment of interest. This development opens the potential to utilise a wide range of organic semiconducting polymers that have been previously developed over the past few decades for transistor and solar cell applications.

Question: What's the electrolyte?
The anisotropic expansion of primary grains, especially at a high state of charge (SOC), results in microcracks in NCM-based secondary particles. The morphology changes of the LLO microspheres after 200 cycles at the cut-offs of 4.8 V and 4.5 V are studied by SEM in Fig. S3.† The LLO microspheres cycled at the cut-off of 4.8 V show some obvious cracks, especially for large particles. But for the LLO particles cycled at 4.5 V, there are no obvious cracks. The structural evolutions of the LLOs at the cut-offs of 4.8 V and 4.5 V are investigated by STEM and EELS, as shown in Fig. 4 and S4–S8.† The cross-sections of both cycled LLOs are shown in Fig. S8,† in which the porous structure can still be found. The elemental maps exhibit heterogeneous distribution of TM elements in both cycled LLOs (Fig. S5 and S6†). The intergranular space is mainly filled with F and C containing compounds while the surface is mainly coated with P containing compounds for both cycled LLOs. The low magnification HAADF-STEM image (Fig. 4(a)) shows some microcracks in the cycled LLOs at the cut-off of 4.8 V. The high resolution HAADF-STEM image with the FFT and inverse FFT patterns (Fig. 4(b and c)) confirms the entire transformation from layered to rock-salt phases on the surface of LLOs at the cut-off of 4.8 V. The LLOs at the cut-off of 4.5 V undergo transitions from layered to layered/rock-salt mixed and rock-salt phases over long-term cycling (Fig. 4(d–f)). These results confirm the mitigated phase transition for LLOs over long-term cycling at the low cut-off of 4.5 V, which is probably ascribed to the reduced side reaction on the electrode/electrolyte interface.

Question: What's the electrolyte?
Hybrid organic–inorganic crystals are unique materials that have been attracting increasing interest in the last few years due to their physical properties and potential applications in different fields, such as photovoltaics, lithium batteries, and photomechanic materials, between others. Among these applications, the development of high conductivity solid state electrolytes for fuel cells, batteries and solar cells is one of the most explored areas, in comparison with the polymers electrolytes that generally show low conductivity. In this sense, they are comparable with the classical ceramic conductors, such as doped lithium titanium phosphate, that allows fast ion transport. However, these materials present the considerable disadvantage of fragility and, in some cases, more importantly toxicity. In order to overcome this problem, a new type of materials have been proposed: the plastic hybrid materials. Although plastic crystals were described in the 60's, there is no rule to predict which cation and anion combinations will yield plastic crystalline materials and which will form salts that melt before any rotator phase is achieved. It deserves to be noted that a plastic crystal has a long-range structural order but short-range disorder, which is typically due to the occurrence of rotational motions of the constituents. This plastic phase can be seen as a mesophase between the solid and liquid phases that is often found in molecules with globular structures. This means that they are symmetrical around their center (CH4, CCl4, NH4 pentaerythritol, etc.); or they make a sphere by rotation around an axis (cyclohexane, camphor, etc.). The combination of two or more units to form hybrid materials can be desirable to enhance the multifunctionality of the system, for example doping plastic crystalline phases with a lithium imide salt for application as solid electrolytes in lithium batteries. An alternative is to combine the physical properties by tuning different constituents: ferroelectricity from polar molecules and long-range magnetic order from magnetic anions.

Question: What's the electrolyte?