milerssliu/battery-device-data-qa huggingface dataset:
qas: question: What's the electrolyte?
context: According to the SEM images in Fig. 4c and S16,† the basic skeleton of FeCO3@IF after OER remains almost the same compared with the electrode before OER. However, the FeCO3 cubes are covered with lots of nanosheets, which grow vertically on the cubes and are connected to each other. According to Fig. S17,† it is easy to observe the formation of a nanosheet array on the surface of the area of FeCO3@IF without FeCO3 cubes, which is the same as the surface morphology of the FeCO3 cubes after the OER process (Fig. 4c). The TEM image in Fig. 4d further confirms the formation of nanosheets. The blurry lattice fringes in the HRTEM image (the inset in Fig. 4d) suggest that the newly generated iron oxo/hydroxides have a high degree of amorphization. Therefore, the generated iron-based oxo/hydroxides are not observed in the XRD pattern (Fig. 4a). Notably, the high degree of amorphization is beneficial for the exposure of more catalytic sites and accelerating mass transfer. Furthermore, the phases with a high degree of amorphization also possess abundant unsaturated electronic configurations, which may improve the adsorption of reactants. The amorphous iron oxo/hydroxides are efficient catalytic sites for OER. More importantly, the vertical nanosheet arrays can promote the penetration of the electrolyte and bubble diffusion compared with cumulate nanoparticles and interlaced nanowires (Fig. S18†). The in situ generated interconnected nanosheets also have a strong interaction with the IF substrate, which is beneficial for maintaining good structural stability and high electron transfer efficiency. According to the SEM and XRD results, FeCO3 does not completely transform into oxo/hydroxide nanosheets, because of diffusional and electrochemical limitations. The partial surface in situ self-reconstruction causes FeCO3@IF to obtain novel and stable hierarchical structures during the OER process (Fig. 4e), with improved mechanical strength and rich diffusion pathways. Therefore, FeCO3@IF shows high OER catalytic activity and stability.
qas: question: What's the anode?
answers: answer_id: 181049
question_id: 66159
text: Bi
question: What's the electrolyte?
answers: answer_id: 181075
question_id: 66160
text: Mg(N(SO2CF3)2)2/acetonitrile
question: What's the anode?
answers: answer_id: 181050
question_id: 66162
text: Mg-alloyable Sn
question: What's the electrolyte?
answers: answer_id: 181076
question_id: 66163
text: Mg(N(SO2CF3)2)2/diglyme
context: The use of Mg-alloyable metallic anodes is another promising approach to enhancing the viability of MIBs. This is mainly because the Mg alloying/dealloying process occurs slightly above the Mg plating/stripping potentials, and the surface passivation problems of Mg in conventional electrolytes is expected to be alleviated to a great extent. Indeed, reversible Mg alloying/dealloying behavior on bismuth has been confirmed in conventional electrolytes by several researchers (e.g., Bi nanoparticles in Mg(N(SO2CF3)2)2/acetonitrile; Bi nanotubes in Mg(N(SO2CF3)2)2/diglyme; and Bi nanocrystals in Mg(N(SO2CF3)2)2/diglyme). Bi anodes have shown reasonable cyclability and rate performance in a nanometric form. Mg-alloyable Sn was also studied for use as MIB anodes. Sn can deliver a higher specific capacity than Bi (903 mA h g−1 for Sn + 2Mg2+ + 4e− → Mg2Sn and 385 mA h g−1 for 2Bi + 3Mg2+ + 6e− → Mg3Bi2) and can alloy/dealloy Mg at a lower potential than Bi (0.15 and 0.25 V vs. Mg/Mg2+ for Sn and Bi, respectively). Despite the theoretical prediction that nanometric Sn can act as a high-capacity MIB anode, pure Sn has shown limited electrochemical performance. For example, though pure Sn delivered a capacity of ca. 900 mA h g−1 during the 1st magnesiation (complete conversion of Sn to Mg2Sn), the capacity abruptly dropped to ca. 200–300 mA h g−1 after the 1st magnesiation, and continuously declined with repeated charge/discharge (C/D). Furthermore, pure Sn often requires the application of potentials close to, or even lower than, the thermodynamic Mg plating potential for the activation of an alloying process.
qas: question: What's the cathode?
question: What's the electrolyte?
answers: answer_id: 181063
question_id: 66160
text:  5 wt% FEC
question: What's the electrolyte?
answers: answer_id: 181064
question_id: 66163
text: carbonate-based 
context: The plating and stripping behaviors of the LiF@Po–Li electrodes are observed by SEM after the Li deposition of 1 mA h cm−2 at a current density of 0.5 mA cm−2 with an EC/DEC:3/7, 1.3 M LiPF6, and 5 wt% FEC electrolyte (Fig. 3). All the electrochemical experiments are performed with carbonate-based electrolytes. It has been well known that the ether-based electrolytes, especially the DME/DOL system, exhibit better electrochemical properties compared to carbonate-based electrolytes in LMBs thanks to their stable SEI layer formation and more freedom to choose additives. However, the ether-based electrolyte is not suitable for various commercial cathode material due to its instability above 4.0 V vs. Li/Li+. In this regard, carbonated-based electrolytes should be explored for their electrochemical properties in upcoming high energy density LMBs. The electrodes are washed with dimethyl carbonate (DMC) to remove residual salts before SEM observation. The Li metal plated on the bare Li electrode shows a mossy, porous and dendritic morphology with an 11.8 μm thickness and 59% porosity (Fig. 3a, b and ESI Note 1†). In contrast, the Li metal plated on the LiF@Po–Li electrode exhibits a smooth and film-like morphology with significantly reduced porosity (Fig. 3c, d and S7†). The cross-sectional view of the LiF@Po–Li electrode after plating clearly shows that a 6.8 μm-thick dense Li film is deposited on the LiF@Po–Li electrode with 28% porosity (Fig. 3d). The stripping behavior is also monitored. As shown in Fig. 3e and f, the bare Li electrode has high-density craters with sizes ranging from 10 μm to 50 μm after the Li stripping. This non-uniform surface morphology is attributed to the localized current density caused by the inhomogeneous SEI layer. In contrast, the LiF@Po–Li electrode has a smooth and conformal surface without noticeable holes over a large area after Li stripping (Fig. 3g and h). This improvement in plating and stripping behaviors of Li is attributed to the LiF@Po protective layer, which enables a uniform Li ion concentration and current density over the Li electrode by suppressing the electrolyte decomposition.
qas: question: What's the electrolyte?
context: Supercapacitors are a class of energy storage devices found commonly in hybrid electric vehicles, camera components and used as backup power systems. One class of supercapacitors, called electric double layer capacitors (EDLCs), are a popular option for commercial applications. In EDLCs, electrolyte ions are adsorbed onto the electrode/electrolyte interface of high-surface area carbon and charge is stored solely via this electrostatic double layer. Due to this charge storage process, the structural integrity of the electrode is maintained resulting in high power densities and cycle lifetimes of over one million cycles. One major drawback of these devices is their low energy density, which limits their use in many applications. To improve the energy density of supercapacitors, many transition metal oxides such as V2O5, Ni(OH)2, Co3O4, RuO2, MnO2 and WO3 have been investigated. Unlike carbon-based materials, transition metal oxides undergo faradaic reactions that facilitate charge storage. Due to accessible redox states, transition metal oxides have much higher energy densities, but most suffer from low conductivity and poor cycling stability. In particular, tungsten oxide has been suggested as a potential alternative for supercapacitor electrode materials due to its redox active properties. Recent efforts have focused on improving tungsten oxide containing supercapacitors including their electrochemical performance, rate, and cycling stability in order to improve this material for energy storage applications.
qas: question: What's the electrolyte?
answers: answer_id: 181066
question_id: 66160
text: 0.1 M NaOH
context: For electrochemical activation of the CRLE two electrodes were placed in a beaker in a distance of approximately 10 cm. A reference electrode (Ag/AgCl 3 M KCl) was placed in close proximity to the electrode to be activated. The second CRLE served as inert counter electrode. In screening experiments different activation potentials and polarisation time were tested at room temperature using 0.1 M NaOH as electrolyte (the results are shown in ESI-7†). Polarisation at 1800 mV for 90 s yielded the best electrode performance at short activation time (Table 1).
qas: question: What's the electrolyte?
answers: answer_id: 181067
question_id: 66160
text: CuInP2S6
context: The listed physical parameters are essential for designing a new generation of electronic devices with significantly improved sensitivity and time response. For instance, the high piezoelectric activity of near room temperature ferroelectrics Sn2P2S6, whose Tc ≈ 337 K, can compete with well-known BiFeO3, currently one of the top choices for switchable ferroelectric diodes. Near room temperature spontaneous polarization of Sn2P2S6 can serve as a base for non-volatile ferroelectric random-access memory (FERAM) elements, at the same time significantly miniaturizing the designed systems. The first steps of such practical exploits have been recently observed for layered room-temperature ferroelectric CuInP2S6, demonstrating that reversible polarization switchability with an on/off ratio of about ∼100 can be achieved for ferroelectric flakes with the thickness reaching an impressive limit of ∼4 nm. Due to locally controlled ion conductivity and giant negative electrostrictive coefficients, CuInP2S6 is also considered as a solid electrolyte for boosting sodium and lithium battery performance. Similarly, 2D superparaelectric Sn2P2S6 with a large dielectric constant was also proposed for the same purpose. The high photoelectric conversion efficiency of Sn2P2S6 allowed exploration of the ultrafast shift-current behaviour, comparable only to the performance of SbSI, CdSe, and CdS. These properties can be utilised for the novel design of the band edge shift current based photovoltaic devices, pushing the solar cell energy harvesting towards their theoretical limit. Additionally, Sn2P2S6 ferroelectrics have prominent photorefractive properties in the near-infrared spectral region, which makes them suitable for highly efficient acousto-optic and holographic devices.
qas: question: What's the electrolyte?
context: 7Li magic-angle spinning (MAS) ssNMR spectroscopy was performed to trace the local environment of Li. Fig. 2d and S4a† shows the 7Li projection magic-angle turning and phase-adjusted sideband separation (pjMATPASS) spectra for the pristine, two-cycled and treated LMO. The pristine LMO showed two isotropic peaks resulting from Li in the octahedral site (LiO6). The main peak with a shoulder at around 748 ppm comes from Li in the Li layer and the one at around 1500 ppm can be attributed to Li in the TM layer. For pristine LMO, the small peak at around 0 ppm was due to the residual Li2CO3. The main peaks at around 748 ppm and 1500 ppm remained in the two-cycled LMO samples (Fig. S4a†). The sharp signal with enhanced intensity at around 0 ppm was mainly due to the solid electrolyte interphase (SEI) components, such as Li2CO3 and LiF. The treated T-LMO sample exhibited that some Li-ions remained in the TM layer, as for LMO and two-cycled LMO. The remaining sidebands at around ±250 ppm in T-LMO came from a peak at around 0 ppm. Besides the similar peaks in LMO, a new peak appeared at around 529 ppm in T-LMO, which can be ascribed to Li in the tetrahedral site, like that in LiMn2O4. A broad peak at around 660 ppm corresponds well with that of the Li2Mn4O9 reference with Li in the tetrahedral site (Fig. S4b†). Although a small amount of disordered shells may exist in the T-LMO sample, their intensities are too low to be detected here, which might be overlapped by the strong NMR signal associated with Li contained in the crystalline core of the particles. The T-LMO curve was deconvoluted by the standard reference spectrum (black curve), which showed that T-LMO consists of 35.5% LMO, 16.9% LiMn2O4 and 47.6% Li2Mn4O9. The NMR spectra result provides direct evidence that new spinel phases appear in the T-LMO, which may be due to cation rearrangement.
qas: question: What's the anode?
answers: answer_id: 181051
question_id: 66159
text: Si@CTSC, Si@ALGC, Si@PVDFC and Si/PVDF
question: What's the electrolyte?
answers: answer_id: 181078
question_id: 66160
text: 1 M LiPF6
context: For the half-cell tests, the electrochemical properties were evaluated using a CR2032 corn-type cell. The cells were prepared in an Ar-filled glove box with H2O and O2 concentrations <0.1 ppm. Si@CTSC, Si@ALGC, Si@PVDFC and Si/PVDF were used as the anodes (diameter: 14 mm), and Li metal foil was used as the counter electrodes (thickness: 300 μm and diameter: 12 mm). A Celgard 2400 polypropylene membrane was used as the separator. The electrolyte was 1 M LiPF6 in a mixture of ethylene carbonate (EC), dimethyl carbonate (DMC), diethyl carbonate (DEC) (1:1:1 by vol) with 5 wt% fluoroethylene carbonate (FEC). The electrolyte amount was 5 g A h−1. The electrochemical tests were carried out after letting the assembled cells stand for 24 hours to ensure full infiltration of the electrolyte. The GCD measurements were carried on a Land CT2001A system from 0.01 to 2.5 V. CV measurements were performed with sweep rates from 0.2 to 1.2 mV s−1 using a CHI660E work station. The frequency for the EIS measurements ranged from 100 kHz to 10 mHz. GITT tests were carried out using a constant current pulse with a duration of 10 min and a relaxation process over 10 min.
qas: question: What's the anode?
answers: answer_id: 181052
question_id: 66159
text: Ti3C2Tx-based materials
context: Ti3C2Tx-based materials have been widely reported as anode materials for supercapacitors and hybrid supercapacitors with the acid electrolyte. Here, the modified Ti3C2Tx MXene (400-KOH-Ti3C2) samples were synthesized based on a previous report. The XRD pattern (Fig. 1a and S1†) reveals that the diffraction peaks of 400-KOH-Ti3C2 shift to a lower 2θ angle compared with those of the original Ti3C2Tx, indicating the increase of interlayer distances after KOH treatment and calcination. In addition, the intensity of partial diffraction peaks for 400-KOH-Ti3C2 is slightly weaker than that of original Ti3C2Tx, suggesting that some feature of the Ti3C2Tx diffraction peaks is shielded by the K+ intercalation into the Ti3C2 MXene layer. Raman spectroscopy (Fig. 1b) and XPS tests (Fig. S2†) were carried out to further manifest the purity and chemical composition of the as-obtained 400-KOH-Ti3C2 samples. To clearly reflect the interlayer spacing for 400-KOH-Ti3C2 samples, the SEM and TEM images are given in Fig. S3† and 1c, respectively. It can be found that 400-KOH-Ti3C2 consisted of stacked MXene nanosheets. The corresponding HRTEM image shows that the interlayer distance of 400-KOH-Ti3C2 is 1.17 nm (Fig. 1d), much larger than that of the original Ti3C2Tx (0.98 nm, Fig. S4†), further confirming the expansion of the interlayer distance after KOH treatment and calcination. In addition, the scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) mapping images of 400-KOH-Ti3C2 clearly indicate that Ti, C, O, F and K elements are homogeneously distributed in all MXene sheets (Fig. S5†).
qas: question: What's the electrolyte?
answers: answer_id: 181084
question_id: 66160
text: Ni(NO3)2·6H2O (0.03 M) and Fe(NO3)3·9H2O (0.01 M)
context: The M2+–Fe LDHs (M = Ni, Zn) nanosheets were prepared using a facile electrosynthesis method. Typically, nickel foam (NF, 10 × 30 × 0.05 mm3) was sonicated in 2 M HCl solution for 15 min and subsequently rinsed with water and ethanol to ensure a clean surface. The electrodeposition was carried out in a standard three-electrode system cell containing NF as the working electrode, Pt plate as the counter electrode and Ag/AgCl (3 M KCl) as the reference electrode. The electrolyte for the electrosynthesis of NiFe LDH contained Ni(NO3)2·6H2O (0.03 M) and Fe(NO3)3·9H2O (0.01 M). The total cation concentration in the electrolyte was maintained at 0.04 M. The potentiostatic deposition was then carried out at −1.0 V vs. Ag/AgCl for 300 s at room temperature. The obtained NiFe LDH nanosheets were carefully withdrawn and rinsed thoroughly with water and ethanol and left to dry at 45 °C. The NiZnFe LDHs nanosheets were prepared via a similar method, by replacing Ni(NO3)2·6H2O (0.03 M) with a mixture of Ni(NO3)2·6H2O (0.027 M) and Zn(NO3)2·6H2O (0.003 M).
qas: question: What's the electrolyte?
context: EELS spectra are obtained from the thin edge of cycled LLOs as labelled by the orange lines in Fig. 4(a and d) to study oxygen vacancies and TM valence states. Detailed comparisons of O-K, Ni-L, Co-L and Mn-L spectra are presented in Fig. 4(g–j) and S7.† For O-K edges, the intensity of the prepeak (∼530 eV) is sensitive to the valence states of TM ions. The intensity of this prepeak decreases drastically from the interior of the particle to the surface and almost disappears at the surface of the cycled LLOs at the cut-off of 4.8 V (Fig. S7†), indicating a significant decrease of TM valence states. This matches well with the fine changes of Mn-L edges in Fig. 4(h), which show a chemical shift (∼2.5 eV) toward the lower binding energy on the surface (0–10 nm depth), as compared with the cycled bulk (≥30 nm depth). These signatures demonstrate that the majority of Mn ions start to shift to a lower valence at a depth of 20 nm beneath the surface of cycled LLOs at the cut-off of 4.8 V, while for the LLOs cycled at 4.5 V, the reduced valence of dominant Mn ions occurs in the top 10 nm layer beneath the surface (Fig. 4(j)). The valence decrease of Mn ions in LLOs is usually accompanied by Mn dissolution into the electrolyte during cycling, which is measured by ICP-OES as shown in Fig. S8.† The Mn concentration dissolved in the electrolyte at the cut-off of 4.8 V after 100 and 200 cycles reaches 139 and 267 ppm, respectively, which are much higher than the 56 and 97 ppm at 4.5 V. These results confirm the reduced Mn dissolution into the electrolyte for the LLOs cycled at the low cut-off of 4.5 V.
qas: question: What's the electrolyte?
answers: answer_id: 181089
question_id: 66160
text: LP30 + FEC
context: For the first cycle in LP30 a more apparent “pitting” peak is observed that occurs at an earlier time compared to LP30 + FEC (occurring at ∼78% and ∼92% capacity, respectively for 0.5 mA cm−2). Other studies have suggested that this is due to inhomogeneous dissolution of the lithium whiskers that result in dead Li formation and early peaking behaviour. However, the lower plating efficiency quantified with in situ NMR can also lead to the early peaking behaviour observed when lower amounts of microstructures are present. With 1 and 2 mA cm−2, the peaking in the first cycle (where the stripping current is kept at 1 mA cm−2) occurs at 85% and 89% capacity respectively. This correlates well with the in situ NMR, which indicated higher plating efficiencies for the higher current densities in LP30. The voltage traces are flatter for the LP30 + FEC electrolyte, as compared to those for LP30, consistent with both the higher plating efficiency seen in the in situ NMR and of studies showing minuscule dead lithium formation in LP30 + FEC. The lower overpotential observed for LP30 + FEC is somewhat consistent between cells (Fig. S2–S4†), but the overpotential is affected both by the resistances in the cell (in particular of the SEI) and the surface area (which increases during electrodeposition) accounting for variations between cells.
qas: question: What's the anode?
answers: answer_id: 181093
question_id: 66159
text:  titanium 
question: What's the electrolyte?
answers: answer_id: 181111
question_id: 66160
text: alkali 
question: What's the anode?
answers: answer_id: 181094
question_id: 66162
text: titanium
question: What's the electrolyte?
answers: answer_id: 181112
question_id: 66163
text: (e.g. NaOH and Ba(OH)2 solutions)
context: (2) A Ti metal precursor is anodized in an alkali electrolyte (e.g. NaOH and Ba(OH)2 solutions). The alkaline anodization (Fig. 6B) could be considered an electro-assisted hydrothermal-like process with 2 stages where TiO2·2H2O anodized from the titanium anode reacts with the hot alkaline surroundings generated by a continuous electric field. In the first stage, a fast anodic reaction on the titanium surface creates a thin TiO2·2H2O nanosheet layer (eqn (1) and (2)) which would react with alkali to form titanate nanowire bundles on the titanium anode (eqn (3)). In particular, it should be mentioned that the OH− concentration should be above 4 M to ensure the formation of titanate rather than titania. In the second stage, the anodized TiO2·2H2O would also break down and disperse into the electrolyte to form a 3D hierarchical porous structure with a large specific surface area.
qas: question: What's the electrolyte?
answers: answer_id: 181113
question_id: 66160
text: LP30 + FEC
context: According to the simulation, the number of moles per surface area formed in the two electrolytes, NSEI (Fig. S17a†) is also greater for the LP30 + FEC electrolyte, indicating a thicker SEI is being formed. We have estimated the thickness of the SEI by using eqn (13) and assuming it to be pure Li2CO3 so as to provide a qualitative understanding of the extent of SEI formation. Averaging over the whole experiment (74 hours) the SEI formation rate is 6.1 nm h−1 in LP30 and 12 nm h−1 for LP30 + FEC. The values are relatively large and seem to overestimate the thickness of the SEI but are on a similar scale to what was estimated in an earlier isotope exchange study (14 nm h−1 in LP30). One possible reason for this overestimation of thickness is the assumption that all of the reduced electrolyte species are deposited to form the SEI. However, it has been shown experimentally that a wide range of the reduced electrolyte species are soluble and go into the electrolyte. We also note that the comparison of SEI thicknesses needs to be interpreted with caution as the chemical composition and density is expected to differ between the two electrolytes.
qas: question: What's the electrolyte?
answers: answer_id: 181114
question_id: 66160
text: 1.25 M LiClO4
context: Next, the annealed WO3−x film was assembled into an electrochromic device to test its functionality. The device structure is shown in Fig. 3a, in which the FTO glass is used as the transparent electrode. The electrolyte with 1.25 M LiClO4 in a mixed solvent was used in the electrochromic device to achieve the insertion and extraction of Li+ ions in the WO3−x film. The device in the bleached state shows a high transmittance in both the visible and infrared wavelength range (Fig. 3b), while in the colored state, the transmittance of the electrochromic device decreases significantly. At the wavelength of 680 nm, the transmittance difference between the two curves is around 70%. In the wavelength range of 700–1000 nm, the transmittance of the colored state is even less than 3%, indicating the excellent near infrared light shielding ability. Hence, in the scorching summer, smart windows made of this electrochromic WO3−x film can keep the room cool by blocking heat radiation. Fig. 3c shows the photographs of the packaged electrochromic device in the coloring and bleaching process. A series of different color states from light to deep blue can be easily obtained by adjusting the applied bias from −3.5 V to 3.5 V, which may have potential applications in the field of electrochromic displays.