milerssliu/battery-device-data-qa huggingface dataset:
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.

Question: What's the electrolyte?
Answer: TDAC-containing
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).

Question: What's the electrolyte?
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.

Question: What's the electrolyte?
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.

Question: What's the electrolyte?
To meet the ever-increasing energy storage demand in electric vehicles and stationary storage systems, a substantial increase in the energy densities of the current Li-ion batteries (LIBs) is essential. This motivates researchers to develop alternate chemistries superior to those based on conventional LiFePO4 and LiCoO2 cathode materials. In this regard, Li–S batteries stand out among their peers because of their high energy capacity. Li–S batteries operate via a conversion based reduction reaction of sulfur (S) with Li (16Li+ + S8 + 16e− ↔ 8Li2S), leading to an exceptionally high theoretical energy density of ∼2500 W h kg−1—five times more than that of conventional LIBs (387 W h kg−1 for LiCoO2/graphite batteries). Additionally, the abundant availability and environment friendly nature of S makes it an attractive cathode material. Despite enormous potential, the practical application of Li–S batteries with liquid electrolyte systems is hindered by issues such as large volumetric changes of S and Li2S (∼80%), and the insulating nature of S and Li2Sx. The reduction of S to Li2S during the discharge cycle follows a multistep reduction reaction process, including the formation of highly soluble long-chain polysulfides (Li2Sn, 4 ≤ n ≤ 8), which are produced as intermediates of this process. Such polysulfides shuttle towards the Li anode which leads to chemical short-circuits and an unstable SEI formation on the Li anode. These polysulfides dry out the liquid electrolyte during long-term cycling which severely affects the performance of the cell. The situation is further complicated by the high loading of S on the cathode (>70% S loading, >3 mgsulfur cm−2) during cycling, which intensifies polysulfide dissolution and volume changes, and enforces structural and morphological variations. Overall, such characteristics of the Li–S system result in self-discharge phenomena, poor capacity retention and low coulombic efficiency. On the other hand, the instability of Li anodes with organic liquid electrolytes is also well-known. Li forms mossy or needle like dendritic structures upon cycling which can potentially pierce the conventional polypropylene separators, resulting in internal short circuits of the cells. To solve these problems, various strategies have been explored for both the S and the Li electrodes. For example, synthesizing S composites with carbonaceous materials and/or surface coating the cathodes with conducting polymers have helped in trapping polysulfides. Tuning the properties of organic electrolytes using different additives has been beneficial too. On the Li side, efforts include ex situ coating of Li with polymer- and carbon-based materials or formation of artificial solid–electrolyte interface (SEI) layers to protect the Li electrode from reacting with the organic liquid electrolyte.

Question: What's the cathode?
Answer: LiFePO4
To meet the ever-increasing energy storage demand in electric vehicles and stationary storage systems, a substantial increase in the energy densities of the current Li-ion batteries (LIBs) is essential. This motivates researchers to develop alternate chemistries superior to those based on conventional LiFePO4 and LiCoO2 cathode materials. In this regard, Li–S batteries stand out among their peers because of their high energy capacity. Li–S batteries operate via a conversion based reduction reaction of sulfur (S) with Li (16Li+ + S8 + 16e− ↔ 8Li2S), leading to an exceptionally high theoretical energy density of ∼2500 W h kg−1—five times more than that of conventional LIBs (387 W h kg−1 for LiCoO2/graphite batteries). Additionally, the abundant availability and environment friendly nature of S makes it an attractive cathode material. Despite enormous potential, the practical application of Li–S batteries with liquid electrolyte systems is hindered by issues such as large volumetric changes of S and Li2S (∼80%), and the insulating nature of S and Li2Sx. The reduction of S to Li2S during the discharge cycle follows a multistep reduction reaction process, including the formation of highly soluble long-chain polysulfides (Li2Sn, 4 ≤ n ≤ 8), which are produced as intermediates of this process. Such polysulfides shuttle towards the Li anode which leads to chemical short-circuits and an unstable SEI formation on the Li anode. These polysulfides dry out the liquid electrolyte during long-term cycling which severely affects the performance of the cell. The situation is further complicated by the high loading of S on the cathode (>70% S loading, >3 mgsulfur cm−2) during cycling, which intensifies polysulfide dissolution and volume changes, and enforces structural and morphological variations. Overall, such characteristics of the Li–S system result in self-discharge phenomena, poor capacity retention and low coulombic efficiency. On the other hand, the instability of Li anodes with organic liquid electrolytes is also well-known. Li forms mossy or needle like dendritic structures upon cycling which can potentially pierce the conventional polypropylene separators, resulting in internal short circuits of the cells. To solve these problems, various strategies have been explored for both the S and the Li electrodes. For example, synthesizing S composites with carbonaceous materials and/or surface coating the cathodes with conducting polymers have helped in trapping polysulfides. Tuning the properties of organic electrolytes using different additives has been beneficial too. On the Li side, efforts include ex situ coating of Li with polymer- and carbon-based materials or formation of artificial solid–electrolyte interface (SEI) layers to protect the Li electrode from reacting with the organic liquid electrolyte.

Question: What's the anode?
Answer: Li
To meet the ever-increasing energy storage demand in electric vehicles and stationary storage systems, a substantial increase in the energy densities of the current Li-ion batteries (LIBs) is essential. This motivates researchers to develop alternate chemistries superior to those based on conventional LiFePO4 and LiCoO2 cathode materials. In this regard, Li–S batteries stand out among their peers because of their high energy capacity. Li–S batteries operate via a conversion based reduction reaction of sulfur (S) with Li (16Li+ + S8 + 16e− ↔ 8Li2S), leading to an exceptionally high theoretical energy density of ∼2500 W h kg−1—five times more than that of conventional LIBs (387 W h kg−1 for LiCoO2/graphite batteries). Additionally, the abundant availability and environment friendly nature of S makes it an attractive cathode material. Despite enormous potential, the practical application of Li–S batteries with liquid electrolyte systems is hindered by issues such as large volumetric changes of S and Li2S (∼80%), and the insulating nature of S and Li2Sx. The reduction of S to Li2S during the discharge cycle follows a multistep reduction reaction process, including the formation of highly soluble long-chain polysulfides (Li2Sn, 4 ≤ n ≤ 8), which are produced as intermediates of this process. Such polysulfides shuttle towards the Li anode which leads to chemical short-circuits and an unstable SEI formation on the Li anode. These polysulfides dry out the liquid electrolyte during long-term cycling which severely affects the performance of the cell. The situation is further complicated by the high loading of S on the cathode (>70% S loading, >3 mgsulfur cm−2) during cycling, which intensifies polysulfide dissolution and volume changes, and enforces structural and morphological variations. Overall, such characteristics of the Li–S system result in self-discharge phenomena, poor capacity retention and low coulombic efficiency. On the other hand, the instability of Li anodes with organic liquid electrolytes is also well-known. Li forms mossy or needle like dendritic structures upon cycling which can potentially pierce the conventional polypropylene separators, resulting in internal short circuits of the cells. To solve these problems, various strategies have been explored for both the S and the Li electrodes. For example, synthesizing S composites with carbonaceous materials and/or surface coating the cathodes with conducting polymers have helped in trapping polysulfides. Tuning the properties of organic electrolytes using different additives has been beneficial too. On the Li side, efforts include ex situ coating of Li with polymer- and carbon-based materials or formation of artificial solid–electrolyte interface (SEI) layers to protect the Li electrode from reacting with the organic liquid electrolyte.

Question: What's the electrolyte?
To meet the ever-increasing energy storage demand in electric vehicles and stationary storage systems, a substantial increase in the energy densities of the current Li-ion batteries (LIBs) is essential. This motivates researchers to develop alternate chemistries superior to those based on conventional LiFePO4 and LiCoO2 cathode materials. In this regard, Li–S batteries stand out among their peers because of their high energy capacity. Li–S batteries operate via a conversion based reduction reaction of sulfur (S) with Li (16Li+ + S8 + 16e− ↔ 8Li2S), leading to an exceptionally high theoretical energy density of ∼2500 W h kg−1—five times more than that of conventional LIBs (387 W h kg−1 for LiCoO2/graphite batteries). Additionally, the abundant availability and environment friendly nature of S makes it an attractive cathode material. Despite enormous potential, the practical application of Li–S batteries with liquid electrolyte systems is hindered by issues such as large volumetric changes of S and Li2S (∼80%), and the insulating nature of S and Li2Sx. The reduction of S to Li2S during the discharge cycle follows a multistep reduction reaction process, including the formation of highly soluble long-chain polysulfides (Li2Sn, 4 ≤ n ≤ 8), which are produced as intermediates of this process. Such polysulfides shuttle towards the Li anode which leads to chemical short-circuits and an unstable SEI formation on the Li anode. These polysulfides dry out the liquid electrolyte during long-term cycling which severely affects the performance of the cell. The situation is further complicated by the high loading of S on the cathode (>70% S loading, >3 mgsulfur cm−2) during cycling, which intensifies polysulfide dissolution and volume changes, and enforces structural and morphological variations. Overall, such characteristics of the Li–S system result in self-discharge phenomena, poor capacity retention and low coulombic efficiency. On the other hand, the instability of Li anodes with organic liquid electrolytes is also well-known. Li forms mossy or needle like dendritic structures upon cycling which can potentially pierce the conventional polypropylene separators, resulting in internal short circuits of the cells. To solve these problems, various strategies have been explored for both the S and the Li electrodes. For example, synthesizing S composites with carbonaceous materials and/or surface coating the cathodes with conducting polymers have helped in trapping polysulfides. Tuning the properties of organic electrolytes using different additives has been beneficial too. On the Li side, efforts include ex situ coating of Li with polymer- and carbon-based materials or formation of artificial solid–electrolyte interface (SEI) layers to protect the Li electrode from reacting with the organic liquid electrolyte.

Question: What's the cathode?
Answer: LiCoO2
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.

Question: What's the electrolyte?
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.

Question: What's the electrolyte?
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.

Question: What's the electrolyte?
Answer: HF
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.

Question: What's the electrolyte?
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.

Question: What's the electrolyte?
Answer: carbonate-based