milerssliu/battery-device-data-qa huggingface dataset:
qas: question: What's the cathode?
answers: answer_id: 103811
question_id: 66158
text: LLOs
question: What's the anode?
answers: answer_id: 103809
question_id: 66159
text: MCMB
question: What's the anode?
answers: answer_id: 103810
question_id: 66162
text: Si/C
context: A pre-lithiated MCMB anode (Fig. S9†) is utilized to match the LLOs cathode for assembling full cells. Since the matched capacity ratio of the anode/cathode is about 1.1 in the full cells, the specific capacity is evaluated based on the weight of the LLO cathode, while the energy density is calculated based on all the components of the full cell. The electrochemical performance of MCMB|LLO full cells is shown in Fig. 5. The full cells show specific capacities of 270 and 256 mA h g−1 at the cut-offs of 4.7 V and 4.5 V with initial coulombic efficiencies of 81.2% and 84.5%, respectively. As exhibited in Fig. 5(b–f), the full cells exhibit a rapid decay of discharge capacity with a capacity retention of only 61.2% after 100 cycles at 0.5C at the cut-off of 4.7 V. By contrast, the full cells show a much enhanced cycling stability with a capacity retention of 84.5% at the cut-off of 4.4 V after the same cycling period. Also, the full cells cycled at 4.4 V show low electrochemical polarization (Fig. S10†), corresponding to the stable discharge voltage as shown in Fig. 5(f). All the components of a typical pouch full cell are shown in Fig. S11,† and the mass fraction of the cathode in a LIB full cell reaches ∼35%. High energy densities of ∼320 and 305 W h kg−1 are achieved for the MCMB|LLO full cells at the cut-offs of 4.7 and 4.4 V, respectively. If a high-capacity Si/C anode is utilized, the energy density of the full cells can be further enhanced. Improved cycling stability of energy density is also confirmed for the full cells cycled at the cut-off of 4.4 V (Fig. 5(f)). The rate capabilities of the MCMB|LLO full cells at the cut-offs of 4.7 V and 4.4 V are illustrated in Fig. 5(d and e) and S12.† The full cells cycled at the cut-off of 4.4 V deliver reversible capacities of 204.6, 186.1, 152.0, and 125.2 mA h g−1 at the high rates of 1C, 2C, 5C and 10C, respectively, which are much higher than those of cells cycled at the cut-off of 4.7 V. Similar to half cells, the full cells exhibit improved electrochemical performance at the low cut-off of 4.4 V. The performance of MCMB|LLO full cells can be further improved by optimizing the electrolyte, capacity ratio of the anode/cathode, prelithiation and full cell design in future studies.
qas: question: What's the electrolyte?
context: The anchoring and catalytic effect of the MoS2 NDs could be more clearly evaluated by cycling batteries at high current densities, which requires a stronger regulation of LPS diffusion and higher redox reaction kinetics at the electrode/electrolyte interfaces. Here, the MoS2 ND/porous carbon/Li2S6 electrodes exhibited discharge capacities of 1156, 1071, 993, 955, 919, and 883 mA h g−1 at 0.1, 0.2, 0.5, 1, 2, and 4C, respectively (Fig. 6c). Accordingly, the capacity retention from 0.1 to 2C was determined to be 79.5% for MoS2 ND/porous carbon/Li2S6. Under the same measurement conditions, the capacity retentions for porous carbon/Li2S6 and MoS2 sheet/porous carbon/Li2S6 were only 1.2% and 22.7%, respectively (Fig. S12, ESI†). Statistical analyses of the discharge/charge voltage profiles (Fig. S12, ESI†) revealed that MoS2 ND/porous carbon/Li2S6 retained the largest amount of polysulfides and the highest conversion efficiency with increasing current densities among the three electrodes. It is worth noting that the highly conductive porous carbon film also contributed to the excellent performance of MoS2 ND/porous carbon/Li2S6 by offering a physical barrier and electron conductive pathway to the polysulfides.
qas: question: What's the electrolyte?
answers: answer_id: 103813
question_id: 66160
text: 0.2 M TDAC
question: What's the electrolyte?
answers: answer_id: 103815
question_id: 66163
text: TDAC-containing
context: As illustrated in Fig. 2a, the TDAC possesses a 2π electron aromatic system that can readily undergo a single electron redox reaction to generate the corresponding TDAC radical dication. Fig. 2b presents the redox potential and solubility of TDAC salt in comparison with those of the state-of-the-art high-potential shuttle molecules. Ideally, the redox potential (protection potential) should be ∼0.2–0.3 V above the upper cut-off voltage of LIBs (normally at 4.3 V). A lower or higher potential outside the range would have the risk of escalated self-discharge during normal operation or an irreversible decomposition of battery components during overcharging. Additionally, a high solubility is desirable since it determines the maximum shuttling current. In these regards, TDAC outperforms all other shuttle candidates with the adequate redox potential of 4.55 V (vs. Li+/Li) and the highest solubility of 0.5 M (Fig. S2†). The electrolyte viscosity before and after the TDAC addition was also investigated. The concentration of 0.2 M was found to be the optimal amount. The viscosity of 0.2 M TDAC electrolyte is 2.72 mPa compared with 2.43 mPa of baseline electrolyte. The electro-kinetics of the TDAC was next investigated by cyclic voltammetry (CV) analysis as shown in Fig. 2c. Even with a high scan rate of 200 mV s−1, TDAC still exhibited a pair of well-defined redox peaks, implying a fast mass transport process within the bulk electrolyte. As shown in Fig. 2d, the diffusion coefficient of TDAC is determined to be 6 × 10−6 cm−2 s−1, which is very comparable with that of other reported shuttles. As displayed in Fig. 2e, after 1000 CV scans, the potential gap between the anodic and cathodic peaks becomes only 60 mV wider, and there is no obvious deterioration of the peak current intensity. Such excellent electrochemical stability has rarely been reported among other 4V-class shuttles. The inset photograph in Fig. 2e presents a shiny Li surface with no bubble generation after storing in TDAC-containing electrolyte solution for six months, indicating a high chemical inertness of the TDAC toward Li metal.
qas: question: What's the electrolyte?
context: Electrochemical impedance spectroscopy (EIS) measurements were performed by Pt sputtering on both sides of the solid electrolyte pellets, and electrochemical characterization was done using SUS electrodes. Biologic VSP-300 models were electrochemically tested at a frequency range of 7 MHz to 100 MHz at 10 mV. Ionic conductivity was calculated using the following expression: where σ is the ionic conductivity (S cm−1), l is the thickness of the sample (cm), A is the measurement area (cm), and R is total resistance (Ω).
qas: question: What's the electrolyte?
context: Fluorination can be used as a strategy to suppress the anionic redox activity, which leads to irreversible oxygen gas formation. It has also been found that the fluorination increases accessible capacity when sufficiently high concentration of fluorine is added. In spite of high fluorine content, there have been some experimental observations which indicate the anionic redox activities of oxyfluorides such as Li2Mn2/3Nb1/3O2F, Li2Mn1/2Ti1/2O2F and Li2MnO2F when they are charged up to 4.5 V or above. In this work, we focus on Li2VO2F material as a comprehensive electrochemical study showed promising results such as good initial capacity and rate capability. However, it suffers from poor cycling performance due, in part, to degradation processes occurring at the electrode–electrolyte interface during extended cycling. We report a comprehensive computational and experimental investigation on the evolution of the anionic redox process in Li2VO2F under typical cycling conditions. The computational simulations suggest that the oxygen species evolve subsequently to peroxide and to superoxide when the cell is charged up to 4.1 V, a potential lower than the commonly used upper limit of 4.5 V to 4.8 V. The formation of superoxide is confirmed using electron paramagnetic resonance spectroscopy. The superoxide remains to be present in the material upon discharge, which suggests that the superoxide formation is not entirely reversible and can contribute to the capacity fading of the material upon cycling.
qas: question: What's the electrolyte?
context: Fig. 6a shows the transfer characteristics of OECTs fabricated with PBTTT with the two different electrolytes. Without DBSA the ON current of the device is ∼−35 μA at a gate bias of −0.8 V and the ON/OFF ratio is ∼102 with an OFF current ∼10−1 μA. This is of relatively poor performance, but when DBSA is added to the gating electrolyte it has a huge effect on the ON current which increases to −3.1 mA with no change in the ON/OFF ratio. The transconductance, gm increases from 0.05 mS (no DBSA) to 3.9 mS (with DBSA). Again, there is a significant decrease in the operation voltage with a drop in the VON value from 0.35 V to 0.12 V (ΔVON = 0.23 V) (Fig. S1 for IDS1/2 plots, ESI†). Adding DBSA also has a strong and positive effect on the transient gate bias pulse characteristics (Fig. 6b) as well as the output characteristics of PBTTT (Fig. 6c and d): IDS increases ∼25 times from ∼−140 μA without DBSA to ∼−3.3 mA with DBSA.
qas: question: What's the electrolyte?
context: Via this NMR study we identify and quantify some of the key SEI parameters – namely the lithium ion transport and the rate of healing – that are important in controlling the nature of lithium metal deposition. Future studies with a much wider range of additives and electrolytes are in progress to use this methodology to help design an optimal SEI layer on lithium metal that achieves uniform plating and stripping at commercially relevant current densities (>0.5 mA cm−2) with high coulombic efficiencies.
qas: question: What's the electrolyte?
context: Current batteries (especially lithium batteries) have been suffering from a bottleneck in safety issues. For example, these batteries are prone to arouse fires or explosions at extreme temperatures or under external forces, giving rise to significant risks in people's daily lives. Fortunately, the quasi-solid-state COG@MnO2//COG@Zn battery developed in this study exhibits fascinating performance in terms of safety. Firstly, we examined its charge–discharge performance at 60 mA cm−3 in a wide temperature range, and the results are shown in Fig. 4d. At room temperature (25 °C), the battery displays a capacity of 10.3 mA h cm−3. When the temperature is decreased to −20 °C, the capacity of the battery decreases to 6.9 mA h cm−3. Moreover, when the temperature is raised up to 100 °C, the battery can still work normally with a capacity of 13.5 mA h cm−3. Overall, the capacity of the battery increases gradually and reaches the peak at 80 °C as the temperature increases from −20 to 100 °C (Fig. 4e). These results indicate that the ion transport through the gel electrolyte is influenced remarkably by the temperature, and the battery can be safely operated in a wide temperature range. Moreover, to evaluate its safety under a variety of extreme conditions, a series of destructive tests were performed on the quasi-solid-state battery. Surprisingly, the battery is still able to power an electronic temperature humidity meter normally even after being damaged under a variety of extreme conditions, such as puncturing, bending, hammering, cutting and cropping (Fig. 4f and Movies S1–S6†), suggesting its superb safety in daily use.
qas: question: What's the electrolyte?
answers: answer_id: 179051
question_id: 66160
text: HF 
context: In situ GIWAXS was used to probe the crystallinity and crystallographic texture of the initial SEI layer formed on copper in 100 ppm added HF electrolyte. The initial SEI, formed by galvanostatically bringing the potential down to 0 V vs. Li/Li+ by cycling at 0.5 mA cm−2, was found to contain crystalline LiF particles as evidenced by the small broad peak at 2.71 Å−1 in the inset of Fig. 8a, corresponding to the (111) crystallographic plane. These LiF crystallites exhibit (111) texturing as shown by the peaks at ±70.5° in the I(χ) analysis (Fig. 8b and S5†), which is reasonable given the face centered cubic rock salt structure of LiF. Scherrer analysis of the LiF (111) peak width from the I(q) data indicates a crystallite size on the order of ∼5 nm, slightly larger than the SEI thickness calculated from both charged passed and XPS depth profiling, suggesting LiF does not form a continuous film. The other SEI components are either amorphous or too thin to characterize with GIWAXS. No crystallographic texture is evident in the SEI formed on copper from an electrolyte without added HF (Fig. S4†). The texturing may only occur in electrolyte with added HF because LiF is formed at higher potential vs. Li/Li+ due to selective HF reduction, and LiF is the only solid product of this reaction. Therefore, the reduction process does not have to compete for reactants (lithium ions, fluorine atoms, electrons) or physical space on the copper surface, resulting in more facile LiF deposition homogenously distributed across the working electrode. In the case without HF, multiple reduction processes (e.g. PF6−, solvent) which yield multiple solid products (e.g. LiF, Li2O, Li2CO3, organic species) all occur simultaneously at the applied scan rates, resulting in more random LiF formation.
qas: question: What's the electrolyte?
context: To further improve the purity of as-obtained H2 gas, a stir-bar was also added inside the electrolyser, and after the ORR continued for ∼50 min with magnetic stirring at a cell voltage of 0.55 V, the residual O2 gas attached in the corners or dissolved in the electrolytes can effectively be removed; there was no obvious O2 residual peak detected from the GC. Also, the residual O2 gas can simply be removed by degassing the system with a vacuum pump. However, extra energy is required for such a process.
qas: question: What's the electrolyte?
answers: answer_id: 179052
question_id: 66160
text: carbonate-based
context: Directing the morphology of lithium metal deposits during electrodeposition is crucial to the development of safe, high energy density batteries with long cycle life. Towards this end, mechanistic insight is imperative to understand the impact of electrolyte components and cycling conditions on lithium morphologies. In this work, we used a standard carbonate-based electrolyte while systematically adding water (0–250 ppm, corresponding to 0–500 ppm HF) in Li‖Cu cells to study the links between electrolyte composition, initial solid electrolyte interphase (SEI) formation, and morphology of electroplated lithium metal using electrochemical characterization, X-ray scattering, X-ray photoelectron spectroscopy, and electron microscopy. Under conditions in which the electrolyte contains several hundred ppm added HF and applied constant currents on the order of 0.5 mA cm−2, this system yields electrodeposited lithium metal with a highly monodispersed columnar morphology. Systematic experimental investigation of the HF reduction process, nature of the initial SEI, and the structure of the electrodeposited lithium metal enable insights to be drawn concerning the underlying mechanisms of columnar lithium formation. This morphology arises from an SEI layer comprising crystalline LiF deposits on the copper current collector surface, formed through selective reduction of HF at high potential, embedded in an amorphous matrix of solvent reduction products. This interphase structure contains fast lithium-ion diffusion pathways which lead to a high nucleation density and uniform growth of lithium metal deposits. The mechanism proposed herein will help to inform future electrolyte additive design and formation cycling protocols for lithium metal batteries.
qas: question: What's the cathode?
answers: answer_id: 228500
question_id: 66158
text: SiC/RGO and polyvinylidene fluoride (PVDF)
question: What's the anode?
answers: answer_id: 228550
question_id: 66159
text:  Li foil 
question: What's the electrolyte?
answers: answer_id: 228480
question_id: 66160
text: 1 M LiTFSI dissolved in TEGDME
context: The electrochemical test of the Li–CO2 battery was performed by using a 2025 type coin cell with a hole (diameter of 1 cm) on the cathode side. As for the cathode preparation, SiC/RGO and polyvinylidene fluoride (PVDF) were blended in N,N-dimethylformamide with a mass ratio of 9:1 to obtain a slurry. The slurry was uniformly deposited on a circular carbon paper with a diameter of 1 cm, and then dried in a vacuum oven at 80 °C. The loading mass of the active material was about 0.5 mg for each pellet. Li foil was used as the anode, and a glass fiber was employed as the separator. 1 M LiTFSI dissolved in TEGDME was used as the electrolyte. The battery was assembled in an argon-filled glove box, and then installed into a self-made sealed quartz bottle. The chamber was repeatedly flushed with pure CO2 prior to the measurements to ensure that the gas in the bottle was pure CO2. Each measurement was performed after a 2 h open circuit potential step to ensure equilibrium in the cell. The electrochemical measurements were carried out using a LAND cycler (CT2001A) and an electrochemical workstation (CHI660D, Shanghai Chenhua). A 500 W Xe-lamp was used as the light source for the tests involving light assistance.
qas: question: What's the cathode?
answers: answer_id: 179090
question_id: 66158
text:  DBHF fiber
question: What's the anode?
answers: answer_id: 179071
question_id: 66159
text: Zn nanosheets@carbon
question: What's the electrolyte?
question: What's the cathode?
answers: answer_id: 179091
question_id: 66161
text: DBHF
context: Inspired by the superior properties of the DBHF fiber cathode, solid-state hybrid batteries were fabricated. As displayed in Fig. 7a and b, a sandwich-type hybrid Zn battery is fabricated based on the DBHF cathode, Zn nanosheets@carbon cloth anode and the gel electrolyte membrane (details in ESI S-4†). Firstly, the stability and flexibility of the fabricated solid state hybrid battery were investigated. As detected in Fig. 7e, good stability in various states, from flat to high degree of bending (Fig. 7g) was achieved during cycling at 2 mA cm−2. The charge/discharge profiles of the last cycle at each bending test (Fig. 7h) indicate the two sets of well-retained voltages corresponding to the redox reaction and ORR/OER processes with negligible shape change at different bending degrees. Therefore, the results demonstrate the good stability and excellent flexibility of the prepared hybrid battery. Next, the high-rate performance of the fabricated hybrid battery was investigated at a series of current densities from 2 to 10 mA cm−2. Good cycling stabilities were achieved at different current densities (Fig. 7f). The charge voltage gradually increases and the discharge voltage decreases with increased current densities. Even at a high current density of 10 mA cm−2, the two sets of charge/discharge voltages are well retained (Fig. 7i), demonstrating its superior high rate capability. Moreover, the flexible hybrid cell exhibits high stability and high efficiency during long-term cycling at the high current density of 6 mA cm−2 (Fig. 7j). After five thousand cycles, the flexible hybrid Zn battery achieves well-defined two-set charge/discharge profiles (Fig. 7k), which demonstrate its high stability and high efficiency. Combining the above results, the solid-state hybrid battery exhibits good stability, superior high rate capability and good flexibility in an air environment, where the Zn-ion battery and Zn–air battery work simultaneously.
qas: question: What's the electrolyte?
context: To test the differences in Li deposition between the two electrolytes further, in situ NMR measurements using pulsed currents were carried out. When applying a pulsed current, short pulses for a period TON are applied, which is followed by a rest period TOFF where no current is passed (schematic, Fig. S5†). During the rest period, TOFF, two main processes occur:
qas: question: What's the electrolyte?
context: Nanostructuring of electrodes is a known method for increasing the power density of lithium-ion (Li-ion) batteries. This can happen because of the much shorter characteristic diffusion times of ions and electrons in nanometer-thick active materials compared to the typical micron-sized active particles. Nanostructured active materials also exhibit a higher contact area with the electrode components supplying ions (the electrolyte) and electrons (the current collector and conductive additives) to the active redox sites. As a result, the time required for fully charging and discharging the electrodes can be shortened from hours to as little as a few seconds.
qas: question: What's the cathode?
answers: answer_id: 179087
question_id: 66158
text: Co-free Ni-rich
question: What's the electrolyte?
context: Aiming to achieve higher energy batteries, researchers have started to revisit the LiNiO2 chemistry with hopes that knowledge obtained from NMC and NCA studies could be applied to LiNiO2 and resolve the issues that were identified decades ago. Furthermore, eliminating the use of cobalt can circumvent the issues surrounding Co such as high toxicity, high cost, and child labor abuse in mining. At the material level, the most popular strategy is the bulk cationic doping to enhance the electrochemical reversibility. With doping strategies, Co-free Ni-rich layered cathode materials are expected to deliver comparable battery performance to NMCs and NCAs. In addition, many studies have been performed on modulating the electrolyte composition to improve the electrode–electrolyte interphase for stabilizing the battery performance. The surface of LiNiO2-based materials is much more reactive than NMC and NCA materials owing to the extreme Ni3+/Ni4+ redox couple. Thus, revealing the origins of surface changes can better inform the advanced design of promising LiNiO2-based materials. At present, most studies rely on ex situ characterization methods to understand the surface degradation of cathode materials, for example, transition electron microscopy (TEM) based techniques for atomic scale structural and chemical analysis, as well as surface sensitive X-ray spectroscopy for ensemble-averaged measurements to probe surface chemical information. The surface sensitive probing techniques typically have low penetrating depths, which makes it difficult to study surface chemistry under practical battery operating environments. Noticeably, the chemical and structural information on the particle surface may be influenced by a range of experimental conditions, including but not limited to, human exhalation, sample storage, and sample preparation during material surface analysis. This can skew observations found in characterization analysis, surface doping, and electrochemical protocol. Therefore, to characterize the surface of LiNiO2 properly, one must understand how the experimental conditions influence overall surface and interfacial chemistries.
qas: question: What's the anode?
question: What's the electrolyte?
answers: answer_id: 179123
question_id: 66160
text: KPF6 in DME
context: The critical property of anode materials is coulombic efficiency. CE at the first cycle is particularly significant since it usually leads to the highest capacity losses due to SEI formation and other irreversible reduction processes. As shown in Chart 5e, a relatively high 1st cycle CE (>60%) is observed for carboxylates, carbonyls 10 and 21, as well as for P30, P31, and P32. For other materials, as well as for some inorganic benchmarks (carbons with a high surface area, phosphorous, FeS2), the CE is even lower. It should be noted that the CE depends not only on the material but also on the electrolyte composition. The tuning of the electrolyte is rarely reported. Some studies indicate that using ether-based electrolytes, such as KPF6 in DME, improves the CE. More attention should be paid to the electrolyte optimization, particularly for the materials that showed low CE with the carbonate-based solutions.