milerssliu/battery-device-data-qa huggingface dataset:
qas: question: What's the electrolyte?
answers: answer_id: 228458
question_id: 66160
text: Lithium conducting garnets 
question: What's the electrolyte?
answers: answer_id: 228459
question_id: 66163
text: garnet 
context: Lithium conducting garnets are attractive solid electrolytes for solid-state lithium batteries but are difficult to process, generally requiring high reaction and sintering temperatures with long durations. In this work, we demonstrate a synthetic route to obtain Ta-doped garnet (Li6.4La3Zr1.4Ta0.6O12) utilizing La- and Ta-doped lanthanum zirconate (La2.4Zr1.12Ta0.48O7.04) pyrochlore nanocrystals as quasi-single-source precursors. Via molten salt synthesis (MSS) in a highly basic flux, the pyrochlore nanocrystals transform to Li-garnet at reaction temperatures as low as 400 °C. We also show that the pyrochlore-to-garnet conversion can take place in one step using reactive sintering, resulting in densified garnet ceramics with high ionic conductivity (0.53 mS cm−1 at 21 °C) and relative density (up to 94.7%). This approach opens new avenues for lower temperature synthesis of lithium garnets using a quasi-single-source precursor and provides an alternative route to highly dense garnet solid electrolytes without requiring advanced sintering processes.
qas: question: What's the electrolyte?
context: In this work, a low upper cut-off voltage of 4.5 V after an initial activation at 4.6 V is proposed and the effects of upper cut-off voltages (4.8 V and 4.5 V) on the stability of cationic/anionic redox chemistries are also studied. We demonstrate the significantly improved reversibility of cationic/anionic redox processes at the low cut-off voltage and the mitigated structural transitions from layered to rock-salt phases along with a valence decrease of Mn ions. Consequently, the LLOs present outstanding capacity/voltage stability over long-term cycling (capacity/voltage retention of 95.2%/92.2% after 200 cycles at 0.5C). The assembled mesocarbon microbead (MCMB)|LLO full cells deliver a high energy density of above 300 W h kg−1 and superior cycling/voltage stability. Compared with the previously proposed methods, this strategy is simpler and enables the use of conventional electrolytes rather than high-voltage ones that have not yet been widely commercialized up to now, which will promote the practical application of LLOs in high energy-density LIBs.
qas: question: What's the electrolyte?
context: In summary, a compressible and elastic N-doped porous carbon nanofiber aerogel was prepared with rGO-wrapped crossed PCNFs and coiled PCNFs as mechanically reinforced structures to support the frameworks. Meanwhile, a hierarchical and porous architecture with open-cell structures existed in N-PCNFAs, which provided plenty of short paths for electrolyte diffusion and enough area for electrochemical double-layer capacitance when N-PCNFAs served as self-supporting and binder-free electrodes. Moreover, N atoms were also introduced into PCNFs as active sites for faradaic redox reactions. Thus, as supercapacitor electrodes, the N-PCNFAs exhibited a high specific capacitance of 279 F g−1 at 0.5 A g−1, with a rate performance of 59% at 20 A g−1. They even reached a capacitance retention of 122% after 10000 cycles because of the N-induced electro-activation, steadily improved wettability of the electrodes during fast charging and discharging, and stable frameworks of N-PCNFAs. Finally, this work presents a wise and simple strategy to prepare CNF-based aerogels with hierarchical structures and heteroatom doping, which also exhibit excellent compressibility and elasticity. These characteristics make them good candidates for energy storage, sensors, adsorption and catalytic materials.
qas: question: What's the anode?
answers: answer_id: 228671
question_id: 66159
text: Li 
question: What's the anode?
answers: answer_id: 228672
question_id: 66162
text: Li 
context: The Li+ transport kinetics at the solid–solid electrode|electrolyte interfaces are crucial for the stable and durable performance of solid-state batteries (SSBs). A poor interface due to mechanical problems and/or (electro-)chemical instabilities will curtail the performance of such batteries. Herein, we present a detailed study on the interfaces of a lithium–sulfur (Li–S) SSB with a Li anode, Li–garnet (LLZO) solid electrolyte (SE), and a sulfur–carbon composite as the cathode. Interlayer gels based on ionic liquids were introduced to improve the interfacial properties of the system. For Li symmetric cells, the strategy resulted in a decrease in cell resistance by about a factor of five and stable voltage profiles with low overpotentials (∼300 mV at 0.4 mA cm−2 after >450 hours). Furthermore, the LLZO SE efficiently blocked the polysulfide shuttle to the Li anode. Due to the advantageous features of the design, good electrochemical performance was obtained, where the Li–S SSB delivered an initial discharge capacity of ca. 1360 mA h gsulfur−1 and a discharge capacity of ca. 570 mA h gsulfur−1 after 100 cycles. Detailed electrochemical and compositional characterization of the interphase layers was performed at the Li anode and sulfur cathode interfaces through X-ray photoelectron spectroscopy (XPS), applying depth-profiling techniques, and scanning transmission electron microscopy (STEM). The results revealed the presence of interphase nano-layers with varying thicknesses on the LLZO surface which contained organic and inorganic species.
qas: question: What's the anode?
answers: answer_id: 228546
question_id: 66159
text: Si–C 
question: What's the electrolyte?
context: CV measurements were conducted on an electrochemical workstation (CHI660A, USA) with glassy carbon as the working electrode (CHI104) and lithium metal as both the reference and counter electrode. A Fc/Fc+ redox couple serves as an internal reference (3.2 V vs. Li+/Li). Standard CR2032 coin cells were assembled inside an Ar-filled glovebox with a 2035 Celgard separator. 30 μL electrolyte was added to each coin cell with barely any electrolyte spilled out during cell crimping. Galvanostatic charge–discharge studies were conducted on a battery cycler (CT2001D, LAND Electronics Co., China). Before assembling full cells, the Si–C anodes were assembled into half-cells for pre-lithiation, which can reduce the initial irreversible capacity. All cells went through three formation cycles at 0.05C, 0.1C and 0.2C, respectively, until the current dropped below 0.05C.
qas: question: What's the anode?
question: What's the electrolyte?
context: Electrides are a unique class of materials, where the electron density is neither localised at an atomic orbital nor fully delocalised like in metals. Instead, their electrons occupy interstitial regions formed by cavities in the crystal structure, where they act as anions. Materials with anionic electrons offer versatile functionalities, such as high electrical conductivity, ultra-low work function, and non-linear optical responses, ranging their applications as electron emitters, battery anodes, and agent catalysts.
qas: question: What's the anode?
question: What's the electrolyte?
context: Wide Angle X-ray Scattering (WAXS) experiments were performed by a Rigaku three pinholes camera, coupled to an Fr-E+ superbright rotating anode microsource (Cu Kα, λ = 0.15405 nm) through a focusing Confocal Max Flux optics (CMF 15-105). Beam diameter was 0.2 mm. Sample-to-detector distance was 28 mm, calibrated by LaB6 powder standard. The sample was raster scanned with a 0.2 mm lateral step, in order to obtain an average pattern from a large crystal volume. 2D WAXS data were centered and calibrated using LaB6 standard and the corresponding 1D WAXS profiles were derived by SUNBIM software.
qas: question: What's the cathode?
question: What's the anode?
question: What's the electrolyte?
context: (4) PEC: a typical PEC process (Fig. 9D) could be regarded as a combination of electrocatalysis, photocatalysis and their synergistic effects from mechanism. On one hand, electrocatalysis could generate functional radicals (e.g. ˙OH) to degrade oxidizable contaminants at the anode and reduce others at the cathode. On the other hand, the photocatalysis subprocess excites e−/h+ to degrade the existing pollutants. In particular, the electrons generated by photocatalysis could migrate along the electric field to the counter electrode by the utilized positive potential (Fig. 9D), which contributes to the reduction of photo-generated holes' and electrons' recombination and thus enhancement of photocatalytic performance. In other words, the increase of bias potential would not only enhance the separation of excitons but also elevate the degree of the electrochemical reaction, which would contribute to the acceleration of PEC performance.
qas: question: What's the electrolyte?
context: The potential of the respective working electrode Ewe and the electrolyte redox potential Esol as function of charge/discharge cycles are shown in Fig. 8a and c. Averaged overpotentials (, see eqn (3)) and CE per cycle for [FeII/III-racEDDHA] and [FeII/III(CN)6] are shown in Fig. 8b and d. In case of [FeII/III(CN)6] a time stable value for was obtained. In case of the [Fe-racEDDHA] complex even a slight decrease in was observed. Thus, no deactivation of the carbon electrode surface was measured during repetitive cycling. Excellent CE was observed for both redox systems, indicating the absence of parasitic side reactions and suggesting a good electrochemical stability of all electrochemically active species. The applied procedure of desizing and anodic activation of the CRLE lead to formation of a stable and active carbon surface, which is not degraded or passivated during extended electrolysis. Independent on electrode potential, passivation was not observed in the potential window between +800 mV and −1200 mV vs. Ag/AgCl, which demonstrates the high chemical stability of the surface towards electrochemical degradation processes at the chosen experimental conditions.
qas: question: What's the electrolyte?
answers: answer_id: 179058
question_id: 66160
text: solvated Li+ (electrolyte) cations and Sn2− (electrolyte) anions
question: What's the electrolyte?
answers: answer_id: 179059
question_id: 66163
text: solvated Li+ (electrolyte) 
context: • Challenge: reality often deviates from theory. Because most metal sulfides are electrochemically active, lithium-inserted products are LiyMSx rather than pristine MSx. These materials strongly influence the behaviors of Li–S batteries but have long been overlooked in theoretical calculations. Solvation also plays an important role in triggering the ionization of LiPSs into solvated Li+ (electrolyte) cations and Sn2− (electrolyte) anions. Therefore, relying on the calculated binding energies of Li2Sx species rather than solvated Li+ (electrolyte) cations might lead to misleading results. There remains a need to optimize theoretical models to enhance the rationality and reliability of computation results.
qas: question: What's the electrolyte?
answers: answer_id: 179063
question_id: 66160
text: LP30
context: In contrast, for the higher constant current of 2 mA cm−2, a close to constant intensity of the metal peak is observed for both electrolyte systems, with a slight increase occurring after passing 5 coulombs (3.25 mA h cm−2, Fig. 3e). Now mNMR is only slightly lower than mechem for both electrolytes, indicating a higher current efficiency for the LP30 electrolyte at 2 mA cm−2. This is tentatively ascribed to the competing reactions of SEI formation and Li deposition where at higher overpotentials, electrodeposition of Li metal occurs more rapidly than the kinetically-limited degradation reaction involving the electrolyte species. The morphology of the lithium deposits for the two electrodes is now very similar (Fig. S7†).
qas: question: What's the anode?
answers: answer_id: 179072
question_id: 66159
text: Mg metal
question: What's the electrolyte?
context: Implementability of Mg metal as an anode in magnesium-ion batteries (MIBs) mostly results from the dendrite-free nature of Mg during electrochemical plating/stripping, although it has been recently reported that the dendritic growth of Mg is dependent on the electrolyte nature and current densities. This feature provides potentially significant advantages to battery fabrication and/or electrochemical performance. For example, Mg metal delivers a higher volumetric capacity (3833 mA h cm−3) than either graphite (841 mA h cm−3) or Li metal (2047 mA h cm−3) in lithium-ion batteries, which enables cell designs that are more compact and flexible. The natural abundance of Mg (29k ppm in the Earth’s crust) is an additional benefit, in comparison with the limits of Li as a natural resource. The reversibility of Mg plating/stripping, however, is quite sensitive to the electrolyte system. The passivation of the Mg surface in conventional electrolytes restricts the versatility of utilizable electrolytes. To overcome this problem, various types of specially designed Mg-compatible electrolytes have been introduced during the past few decades: ‘all phenyl complex’ (APC); ‘magnesium aluminum chloride complex’ (MACC); [(DTBP)MgCl + MgCl2] (DTBP = 2,6-di-tert-butylphenolate); and [PhMgCl + MgCl2]. These electrolytes have shown reasonable levels of reversibility for Mg plating/stripping, but the relatively low anodic stability (≤ca. 3.0 V vs. Mg/Mg2+) and/or the difficulty in reaching high coulombic efficiencies remain problematic if MIBs are to move one step closer to commercialization.
qas: question: What's the cathode?
context: The electrochemical data were collected using assembled 2032-coin cells. The cathode electrode was prepared by mixing the as-prepared MVO microspheres or V2O5·nH2O, carbon black and polytetrafluoroethylene (PTFE) binder in a weight ratio of 6:3:1. The coin cells were assembled using the prepared cathode, zinc metal as the anode, and the prepared PAM–CNF film as the electrolyte and separator. Galvanostatic charge/discharge electrochemical tests were performed on an eight-channel LAND battery analyzer (CT3001A, LAND Electronics Corporation, Wuhan, China) in the voltage range of 0.2–1.6 V. Cyclic voltammetry (CV) measurements were carried out on an electrochemical workstation (CHI 760e) in the potential range of 0.2–1.6 V. Electrochemical impedance spectroscopy (EIS) was carried out by applying an AC potential of 5 mV amplitude in the frequency range of 0.01–100 kHz. A freeze-resistance test was carried out at −18 °C in a freezer. Heat-resistance properties were tested in an EQ-DHG-9015 oven (MTI Inc., Richmond, CA, USA).
qas: question: What's the cathode?
answers: answer_id: 81409
question_id: 66158
text: SSB composite
context: Both chemical and mechanical instabilities play a role in the impedance build-up and capacity fade during SSB cycling. Chemical reactivity issues between conductor and cathode have been well-studied theoretically and experimentally. In this work, we focus on the mechanical failure modes of an SSB composite cathode. The latter consists of an intimate mixture of the solid electrolyte and active cathode particles so that a transport path exists for the Li ions to/from the cathode particles. Good Li-ion transport across the solid electrolyte/cathode particle interface is necessary to minimize the cell resistance and overpotential of the composite cathode. Chemical reactivity at the solid electrolyte/cathode interface can lead to the formation of a reaction layer, which increases cathode impedance. For example, sulfide-based electrolytes have been shown to react with oxide-based cathodes, resulting in overpotential growth and capacity fade. Coating the cathode particles has been shown to mitigate this issue to some extent and improve cycling stability.
qas: question: What's the cathode?
answers: answer_id: 81381
question_id: 66158
text: carbon nanofiber@V2S3 (CNF@V2S3/S) composite 
context: Herein, we designed a type of NiAs-type structured V2S3 nanoparticle by a one-step vulcanization reaction under Ar. The results showed the resultant carbon nanofiber (CNF)@V2S3 composite films show an improved conductance and a high flexibility, which is due to the high conductivity of V2S3 and the catalytic effect of V atoms on the carbonization treatment of CNFs. And the sulfur loaded carbon nanofiber@V2S3 (CNF@V2S3/S) composite cathodes showed a high specific capacitance of 1200 mA h g−1 at 0.1C, an excellent rate capability (retain 78.9% at 2.0C), and an ultralow decay rate per cycle (0.0071% at 2.0C for 1000 cycles). This high rate capability as well as high cycling stability could be due to the high polarity and catalytic activity, and improved conductivity of V2S3 nanocrystals. Furthermore, the enhancement mechanisms of energy storage and reaction kinetics of the composite cathodes via V2S3 have also been discussed.
qas: question: What's the cathode?
answers: answer_id: 81393
question_id: 66158
text:  Li-rich 
context: The lithium-ion battery, which can convert chemical energy to electric energy, has been widely used in portable devices, such as the laptops and mobile phones. However, the pressing demand for high capacity and stability is yet to be solved, especially the cathode, which has been the bottleneck of battery capacity. The Li-rich layered oxide has gained much attention due to the extremely high capacity of over 280 mA h g−1. Recent research has revealed that the extra capacity in the Li-rich oxide comes from the participation in oxygen redox. The complex chemical and structural evolution of the Li-rich cathode has attracted extensive efforts, however, the critical problem of voltage decay remains unsolved with its elusive mechanism.
qas: question: What's the electrolyte?
context: Combining the insights derived from the systematic set of experiments detailed in this report along with complimentary results from literature, we have uncovered a new understanding of the mechanisms underlying the growth of columnar lithium metal. A schematic representation of the proposed mechanism linking electrolyte additive concentration, initial SEI formation, and the resulting growth of lithium columns is shown in Fig. 13. The initially pristine, oxide-free copper surface enables the electrocatalytic reduction of HF at ∼2 V vs. Li/Li+ which forms (111) textured LiF deposits a few nanometers in size on the surface. Two morphologically distinct yet functionally equivalent LiF deposit morphologies are possible – uniform yet discontinuous LiF particles decorating the copper surface or a continuous polycrystalline film – with the former being more probable in this system when considering the substrate roughness and LiF crystallite size. This HF reduction and LiF deposition process slows significantly when HF becomes depleted near the interface. Subsequently, as the potential drops below 1 V, solvent molecules are decomposed on the remaining unpassivated surfaces between and/or on top of LiF particles, forming organic reduction products and slowing further reduction of electrolyte species. While the precise morphology of the LiF particle layer could not be directly imaged, both candidate morphologies shown schematically in Fig. 13 would result in an SEI with similar properties and identical effects on lithium nucleation and growth. Interfaces between individual crystalline LiF particles and/or between LiF particles and the amorphous matrix of solvent reduction products in the initial SEI act as fast lithium-ion diffusion pathways. These pathways serve to homogenize the electronic and ionic properties near the copper surface, enabling a high nucleation density of lithium metal as the potential of the working electrode is brought below 0 V vs. Li/Li+ and electrodeposition of the active material begins via an instantaneous nucleation event. High lithium-ion diffusion within the SEI created by these interfaces, which allows for easier movement of lithium ions laterally across the electrode surface, along with the layer being very thin, allow for uniform, lateral growth of the lithium metal deposits until they bump into one another. After lateral growth is inhibited the deposits are restricted to growing vertically, normal to the working electrode, resulting in the highly monodisperse (110) textured columnar morphology observed. The diameter of these lithium columns can be controlled by varying the current density during electrodeposition (Fig. S8†). Indeed, a columnar morphology may be the intrinsically preferred growth mode of lithium metal. However, such growth may be inhibited by the SEI formed in conventional electrolytes without additives due to non-uniform lithium-ion diffusivity and the presence of “hot spots” where preferential deposition occurs, whereas the nanostructured SEI formed in electrolytes with added HF would allow columnar growth to proceed uninhibited.
qas: question: What's the cathode?
answers: answer_id: 78585
question_id: 66158
text: AC
question: What's the anode?
answers: answer_id: 78587
question_id: 66159
text: CuO nanowires
context: In comparison with MnOx, NiO and Co3O4, TiO2 with lower theoretical capacitance has also been tested as an electrode in SCs. For instance, by using TiO2 nanofibers, activated carbon and a PVA–H3PO4 membrane, a solid-state SC was fabricated, which delivered a specific capacitance of 310 F g−1. Recently, Ta-doped TiO2 nanofibers were synthesized through the electrospinning technique. In 1 M H2SO4, the 2% Ta-doped TiO2 nanofibers could deliver nearly two times higher specific capacitance than the undoped TiO2 counterpart (111 F g−1), which was attributed to the enhanced electronic conductivity of TiO2 stemming from the replacement of Ti4+ by Ta5+ in the lattice after doping. In addition to the most studied metal oxides mentioned above, Fe2O3, V2O5 and CuO have also been applied to SCs as electrodes. The first report on a pure iron oxide electrode composed of particles with sizes of 53 nm has demonstrated a specific capacitance of 256 F g−1 in 1 M LiOH. Recently, both interconnected Fe2O3 and V2O5 nanofibers with rich meso-/macro-pores were obtained via electrospinning and subsequent heat treatment. Owing to the hierarchical porous structure that acts as an excellent conductive highway for efficient electronic transfer and ion permeation, the resultant binder-free Fe2O3 and V2O5 electrodes gave specific capacitances of 255 F g−1 and 256 F g−1, respectively, at 2 mV s−1 in 1 M Na2SO4. Moreover, an all-solid-state ASC based on an Fe2O3 negative electrode and V2O5 positive electrode could be operated at up to 1.8 V and displayed a high energy density of 32.2 W h kg−1 at an average power density of 128.7 W kg−1. In 2012, pure electrospun V2O5 nanofibers with different structures have been synthesized and tested in two studies. These pure electrospun V2O5 nanofibers displayed a capacitance of around 200 F g−1 in both the studies. A high specific capacitance of 620 F g−1 (accounting for ∼35% of their theoretical capacitance) at 2 A g−1 in 6 M KOH was reported by Jose et al. for electrospun CuO nanowires in 2014. In another reference, an ASC device based on electrospun CuO nanowires as the anode and AC as the cathode was constructed and provided an enhanced voltage window (1.6 V), specific capacitance (83 F g−1), and threefold higher energy density (29.5 W h kg−1) than the AC-based symmetric capacitor (1.4 V, 33 F g−1, 11 W h kg−1).