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

Question: What's the cathode?
Answer: SiC/RGO and polyvinylidene fluoride (PVDF)
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.

Question: What's the anode?
Answer:  Li foil
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.

Question: What's the electrolyte?
Answer: 1 M LiTFSI dissolved in TEGDME
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.

Question: What's the cathode?
Answer:  DBHF fiber
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.

Question: What's the anode?
Answer: Zn nanosheets@carbon
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.

Question: What's the electrolyte?
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.

Question: What's the cathode?
Answer: DBHF
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:

Question: What's the electrolyte?
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.

Question: What's the electrolyte?
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.

Question: What's the cathode?
Answer: Co-free Ni-rich
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.

Question: What's the electrolyte?
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.

Question: What's the anode?
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.

Question: What's the electrolyte?
Answer: KPF6 in DME
• Enhancing affinity toward LiPSs promotes surface conversion to decrease the total amount of soluble LiPSs in the electrolyte, thereby ensuring shuttle suppression and high capacity. Metal sulfides with a high surface area, well-designed porosity, enhanced surface polar (functional or defective surface), desired surface selectivity (exposed crystal faces), and tailored crystalline form are a high-priority target.

Question: What's the electrolyte?
In this study, three types of electrolytes were prepared for investigation: 1.0 M LiPF6 in ethylene carbonate/diethyl carbonate (EC/DEC, 1:1 v/v, marked as LPE-EC), 1.0 M LiPF6 in propylene carbonate/diethyl carbonate (PC/DEC, 1:1 v/v, marked as LPE-PC), and 1.0 M LiPF6 in PC/DEC (1:1 v/v, with 0.005 M LiBOB, marked as LPE-PC–LiBOB). All the electrolytes were prepared in an argon-filled glove box.

Question: What's the electrolyte?
Answer: 1.0 M LiPF6 in ethylene carbonate/diethyl carbonate
In this study, three types of electrolytes were prepared for investigation: 1.0 M LiPF6 in ethylene carbonate/diethyl carbonate (EC/DEC, 1:1 v/v, marked as LPE-EC), 1.0 M LiPF6 in propylene carbonate/diethyl carbonate (PC/DEC, 1:1 v/v, marked as LPE-PC), and 1.0 M LiPF6 in PC/DEC (1:1 v/v, with 0.005 M LiBOB, marked as LPE-PC–LiBOB). All the electrolytes were prepared in an argon-filled glove box.

Question: What's the electrolyte?
Answer: 1.0 M LiPF6 in ethylene carbonate/diethyl carbonate (EC/DEC, 1:1 v/v, marked as LPE-EC), 1.0 M LiPF6 in propylene carbonate/diethyl carbonate (PC/DEC, 1:1 v/v, marked as LPE-PC), and 1.0 M LiPF6 in PC/DEC (1:1 v/v, with 0.005 M LiBOB, marked as LPE-PC–LiBOB)
Moreover, cycling stability is a very important parameter of the electrochromic films in practical applications. We have measured the CV curves for more than 200 cycles from −0.6 to 0.9 V. In each cycle, the reversible process of coloring and bleaching can be observed in the annealed WO3−x film. Fig. 4d shows the CV curves for the first, 50th, 100th, 150th and 200th cycle. The CV curves in the first 50 cycles show slight promotion, and remain almost stable without any degradation even after 200 cycles. Such a high cycling stability may originate from the solid nanostructure of the annealed WO3−x film and the prevention of the harmful side reaction at the WO3−x film/electrolyte interface.

Question: What's the electrolyte?
For dual-ion batteries, increasing Qm is also principally possible by, for example, increasing the concentration of redox-active nitrogen atoms in aromatic amines. For such optimized materials, where most of the active units are involved, it is expected that the operation potentials will get higher at least for conjugated structures because polymers with a high positive charge at the backbone are harder to oxidize. It will therefore be important to develop electrolytes for potassium batteries, which are tolerant to high voltages, or to elaborate protective coatings at the cathode surface. Certain progress in the development of high-voltage potassium battery electrolytes has already been achieved.

Question: What's the cathode?
For dual-ion batteries, increasing Qm is also principally possible by, for example, increasing the concentration of redox-active nitrogen atoms in aromatic amines. For such optimized materials, where most of the active units are involved, it is expected that the operation potentials will get higher at least for conjugated structures because polymers with a high positive charge at the backbone are harder to oxidize. It will therefore be important to develop electrolytes for potassium batteries, which are tolerant to high voltages, or to elaborate protective coatings at the cathode surface. Certain progress in the development of high-voltage potassium battery electrolytes has already been achieved.

Question: What's the electrolyte?
To address the challenges facing Li–S batteries, considerable efforts have been made to develop sulfur-based cathode composite materials, modify separators, protect Li anodes, and use conductive interlayers and/or novel electrolyte additives (Fig. 1b). These approaches have all yielded certain encouraging results. However, the above strategies often have variable effects on the performance of Li–S batteries, owing to the specificity and interdependency of the S8–Li2Sn–Li2S (solid–liquid–solid) multistage transformation. For example, the conductive interlayer introduced between the separator and cathode suppresses the migration of LiPSs, which also offers additional electron pathways that cover the top surface of the cathode. This performance enhances the use of active materials and reduces random deposition of Li2S on the surface of the Li anode, thereby restraining dendrite formation and improving the anode stability to a certain degree.

Question: What's the cathode?
Answer: sulfur-based