milerssliu/battery-device-data-qa huggingface dataset:
In general, the solid electrolytes used to develop Na-ion solid state battery systems are based on inorganic solid materials; in particular, oxide-based materials that have high ionic conductivity and are electrochemically and thermally stable are being studied. Among oxide-based materials, Na-β-alumina materials have been mainly studied. Because of their high ionic conductivity, they have been used in all-solid-state batteries until recently. However, they have the disadvantage of being vulnerable to moisture. Another stable oxide-based material is Na3Zr2Si2PO12 (Na super-ionic conductor, NASICON). NASICON solid electrolytes are promising oxide-based Na-ion conducting materials, with a high ionic conductivity of over 10−4 S cm−1 at room temperature and stability to air and moisture. NASICON ceramics are electrochemically stable up to 7 V, making them suitable for use in high voltage batteries. Owing to its stability advantages, efforts have been made to use NASICON in solid-state NIB systems. However, there remains a critical problem in the resistance between solid particle interfaces caused by the fragile and rigid nature of the oxide material itself, regardless of how high the pressure of the solid electrolyte powder is, making it difficult to utilize it in a solid-state battery system.

Question: What's the electrolyte?
Answer: NASICON
3.2.1 Cyclic voltammetry. CV studies have been performed first to optimize the operating potential difference range of the supercapacitor cells. For this purpose, the CV profiles of a typical cell (Cell#4) have been recorded for varying potential difference ranges as shown in Fig. 4a. A close inspection indicates that CV responses show almost rectangular-box like patterns without much deviation, indicating stable capacitive behavior, for the range from 0 to 2.5 V. Thus, all the cells have been electrochemically characterized up to 2.5 V in two electrode configuration, in the present study. This has been confirmed from GCD studies also, as discussed later. It may be noted that the stability window of the dual redox-active electrolyte film is high (∼6.2 V), as discussed above, and the charging voltage of the device is restricted to ∼2.5 V only. The most possible reason for the limited charging voltage of the device is related to the possible reaction(s) of the electrolyte ions with the surface functional groups (carbonyl, carboxyl, hydroxyl, etc.) attached to the activated carbon electrode surface. The electrochemical performance of all the supercapacitor cells (Cell#1 to Cell#4) has been compared, comparing their CV patterns, recorded at a scan rate of 10 mV s−1, as shown in Fig. 4b. Cell#1 (with the GPE without redox additives) shows almost a rectangular pattern, similar to the characteristics of capacitors with carbon electrodes, indicating the dominance of double-layer-type capacitive nature. The CV profiles of Cell#2 and Cell#3 (containing GPEs with single redox additives DPA and KI, respectively) illustrate distinct reversible redox peaks (Fig. 4b). The reversible redox peaks in Cell#2 are associated with the reversible conversion between diphenyl benzidine, DPB (colorless) and DPB (violet), which is initiated after irreversible redox transformation of DPA into DPB (colorless), as shown in the following Scheme (1).

Question: What's the electrolyte?
Electrochromic devices (ECDs) have been widely investigated for application in next-generation displays and smart windows thanks to their highly efficient optical transmittance modulation properties. However, several challenges such as chemical and environmental instabilities and leakage of electrolytes limit their practical applications. In this paper, we report a simple and efficient approach for synthesising ultraviolet (UV)-cured poly(methyl methacrylate) (PMMA) gels that can be used as safe electrolytes. The ECDs fabricated with the 10 min UV-cured PMMA gel electrolyte deliver remarkable device performances with a wide optical transmittance transition (ΔT) of 51.3% at a wavelength of 550 nm under −1.2–0 V bias range and fast switching times (Δt) of 1.5 s and 2.0 s for bleaching and colouration, respectively. In addition, excellent operational stability of 98.9% after 11500 cycles and environmental stability at a wide temperature range of −20 to +70 °C are exhibited. Moreover, a smart electrochromic window system, including an ECD connected with an Arduino circuit, is developed. These smart windows can change colour by simultaneously monitoring the illumination and UV intensities of sunlight.

Question: What's the electrolyte?
Answer: ultraviolet (UV)-cured poly(methyl methacrylate) (PMMA)
Electrochromic devices (ECDs) have been widely investigated for application in next-generation displays and smart windows thanks to their highly efficient optical transmittance modulation properties. However, several challenges such as chemical and environmental instabilities and leakage of electrolytes limit their practical applications. In this paper, we report a simple and efficient approach for synthesising ultraviolet (UV)-cured poly(methyl methacrylate) (PMMA) gels that can be used as safe electrolytes. The ECDs fabricated with the 10 min UV-cured PMMA gel electrolyte deliver remarkable device performances with a wide optical transmittance transition (ΔT) of 51.3% at a wavelength of 550 nm under −1.2–0 V bias range and fast switching times (Δt) of 1.5 s and 2.0 s for bleaching and colouration, respectively. In addition, excellent operational stability of 98.9% after 11500 cycles and environmental stability at a wide temperature range of −20 to +70 °C are exhibited. Moreover, a smart electrochromic window system, including an ECD connected with an Arduino circuit, is developed. These smart windows can change colour by simultaneously monitoring the illumination and UV intensities of sunlight.

Question: What's the electrolyte?
Answer: UV-cured PMMA gel
Li metal is regarded as the best candidate for anode materials because of its high theoretical capacity and negative electrode potential. However, due to the continuous parasitic side reactions and messy growing Li dendrites, the practical use of the Li metal as an anode is seriously limited. An in situ formed artificial solid electrolyte interface (SEI) can commendably solve the above-mentioned problems; however, inevitable cracks and fractures are found during their long-term service due to the existence of inorganic compounds (or alloys) in the artificial-SEI. Herein, a self-repairing alloy for protecting the Li metal anode was prepared via a facile in situ reaction. A long-term cycling life of more than 1800 h and 1400 h was obtained for the self-repairing alloy protected Li metal anode at a practical current density of 2 mA cm−2 and 5 mA cm−2. Even after increasing the deposition capacity to 15 mA h cm−2, no dendrite formation was detected in the self-repairing alloy protective Li anode. This is expected to be a promising strategy in achieving a stable Li metal anode/electrolyte interface and providing a new way of thinking for the development of Li metal batteries.

Question: What's the anode?
Answer: Li metal
Li metal is regarded as the best candidate for anode materials because of its high theoretical capacity and negative electrode potential. However, due to the continuous parasitic side reactions and messy growing Li dendrites, the practical use of the Li metal as an anode is seriously limited. An in situ formed artificial solid electrolyte interface (SEI) can commendably solve the above-mentioned problems; however, inevitable cracks and fractures are found during their long-term service due to the existence of inorganic compounds (or alloys) in the artificial-SEI. Herein, a self-repairing alloy for protecting the Li metal anode was prepared via a facile in situ reaction. A long-term cycling life of more than 1800 h and 1400 h was obtained for the self-repairing alloy protected Li metal anode at a practical current density of 2 mA cm−2 and 5 mA cm−2. Even after increasing the deposition capacity to 15 mA h cm−2, no dendrite formation was detected in the self-repairing alloy protective Li anode. This is expected to be a promising strategy in achieving a stable Li metal anode/electrolyte interface and providing a new way of thinking for the development of Li metal batteries.

Question: What's the electrolyte?
Li metal is regarded as the best candidate for anode materials because of its high theoretical capacity and negative electrode potential. However, due to the continuous parasitic side reactions and messy growing Li dendrites, the practical use of the Li metal as an anode is seriously limited. An in situ formed artificial solid electrolyte interface (SEI) can commendably solve the above-mentioned problems; however, inevitable cracks and fractures are found during their long-term service due to the existence of inorganic compounds (or alloys) in the artificial-SEI. Herein, a self-repairing alloy for protecting the Li metal anode was prepared via a facile in situ reaction. A long-term cycling life of more than 1800 h and 1400 h was obtained for the self-repairing alloy protected Li metal anode at a practical current density of 2 mA cm−2 and 5 mA cm−2. Even after increasing the deposition capacity to 15 mA h cm−2, no dendrite formation was detected in the self-repairing alloy protective Li anode. This is expected to be a promising strategy in achieving a stable Li metal anode/electrolyte interface and providing a new way of thinking for the development of Li metal batteries.

Question: What's the anode?
Answer:  Li metal
As indicated by the above results, the Li/Al-ion electrolyte exhibits better cycle stability than the Al-ion electrolyte. To further investigate the electrolytes, the voltammograms of these electrolytes measured at different scan rates were analysed using the Randles–Sevick equation (Fig. S7†). The calculated Li-ion diffusion coefficients are 2.84 × 10−12 cm2 s−1 and 7.96 × 10−13 cm2 s−1 in the WO3 and the Ti-V2O5 films, and the Al-ion diffusion coefficients are 2.72 × 10−14 cm2 s−1 and 7.99 × 10−15 cm2 s−1 in the WO3 and the Ti-V2O5 films, respectively. The obtained diffusion coefficients are all two magnitudes lower for Al3+ than Li+, owing to the strong electrostatic interaction between trivalent Al3+ and the host lattice, which slows the ion diffusion in the films. For the mixed Li/Al-ion electrolyte, the obtained diffusion curves are between those of the pure Li-ion electrolyte and the pure Al-ion electrolyte (Fig. S7d, h†). Such a performance is much better compared with the coefficient of pure Al-ions in the films, indicating better ion diffusion in the lattices and promoting the cycle stabilities. Previous reports also indicated that the mixed Li/Al-ion electrolyte can promote the cycling performance in Al-anode batteries. The utilization of mixed ion electrolytes can be a promising direction and deserves further investigation.

Question: What's the anode?
Answer: Al
As indicated by the above results, the Li/Al-ion electrolyte exhibits better cycle stability than the Al-ion electrolyte. To further investigate the electrolytes, the voltammograms of these electrolytes measured at different scan rates were analysed using the Randles–Sevick equation (Fig. S7†). The calculated Li-ion diffusion coefficients are 2.84 × 10−12 cm2 s−1 and 7.96 × 10−13 cm2 s−1 in the WO3 and the Ti-V2O5 films, and the Al-ion diffusion coefficients are 2.72 × 10−14 cm2 s−1 and 7.99 × 10−15 cm2 s−1 in the WO3 and the Ti-V2O5 films, respectively. The obtained diffusion coefficients are all two magnitudes lower for Al3+ than Li+, owing to the strong electrostatic interaction between trivalent Al3+ and the host lattice, which slows the ion diffusion in the films. For the mixed Li/Al-ion electrolyte, the obtained diffusion curves are between those of the pure Li-ion electrolyte and the pure Al-ion electrolyte (Fig. S7d, h†). Such a performance is much better compared with the coefficient of pure Al-ions in the films, indicating better ion diffusion in the lattices and promoting the cycle stabilities. Previous reports also indicated that the mixed Li/Al-ion electrolyte can promote the cycling performance in Al-anode batteries. The utilization of mixed ion electrolytes can be a promising direction and deserves further investigation.

Question: What's the electrolyte?
Answer: Li/Al-ion
As indicated by the above results, the Li/Al-ion electrolyte exhibits better cycle stability than the Al-ion electrolyte. To further investigate the electrolytes, the voltammograms of these electrolytes measured at different scan rates were analysed using the Randles–Sevick equation (Fig. S7†). The calculated Li-ion diffusion coefficients are 2.84 × 10−12 cm2 s−1 and 7.96 × 10−13 cm2 s−1 in the WO3 and the Ti-V2O5 films, and the Al-ion diffusion coefficients are 2.72 × 10−14 cm2 s−1 and 7.99 × 10−15 cm2 s−1 in the WO3 and the Ti-V2O5 films, respectively. The obtained diffusion coefficients are all two magnitudes lower for Al3+ than Li+, owing to the strong electrostatic interaction between trivalent Al3+ and the host lattice, which slows the ion diffusion in the films. For the mixed Li/Al-ion electrolyte, the obtained diffusion curves are between those of the pure Li-ion electrolyte and the pure Al-ion electrolyte (Fig. S7d, h†). Such a performance is much better compared with the coefficient of pure Al-ions in the films, indicating better ion diffusion in the lattices and promoting the cycle stabilities. Previous reports also indicated that the mixed Li/Al-ion electrolyte can promote the cycling performance in Al-anode batteries. The utilization of mixed ion electrolytes can be a promising direction and deserves further investigation.

Question: What's the electrolyte?
Answer: Al-ion electrolyte.
In addition, the long-term cycling test at 5C was performed to investigate the cycling performance of all the NVPF-based materials shown in Fig. 3d. The NVPF@5% rGO gave the highest initial discharge capacity of 83.2 mA h g−1, compared with the NVPF (74.6 mA h g−1), NVPF@2.5% rGO (76.4 mA h g−1), and NVPF@7.5% rGO (79.9 mA h g−1). It also exhibited an excellent capacity retention of 94.06% after 1000 cycles, achieving a high average coulombic efficiency (CE) of 99.6% throughout. Therefore, apart from its outstanding rate capability, the NVPF@5% rGO also exhibited an extremely durable cycling performance. Furthermore, due to the high conductivity and uniformity of the rGO carbon network, the ΔV values of NVPF@5% rGO were smaller than that of others in each cycle (inset Fig. 3d). The NVPF@7.5% rGO had a slight increase in polarization compared to the NVPF@5% rGO at 1000 cycles, which could be caused by the uneven carbon network. But the polarization of NVPF increased almost linearly during cycling, which leads to a low CE and poor cycling performance. Moreover, although NVPF@2.5% rGO with an incomplete carbon network can inhibit the increase of polarization before 400 cycles, it still exhibits high polarization after more cycles. The schematic diagram of the Na+ and e− transport pathways in NVPF@5% rGO is shown in Fig. 3e. As shown, because of the robust 3D continuous conductive network structure, the NVPF@5% rGO could not only achieve a highly efficient, ultrafast and continuous transmission of Na+ and e−, but could also build an effective buffer to accommodate volume changes during charge (desodiation)/discharge (sodiation) processes. In addition, the large specific surface area of the rGO carbon network in NVPF@5% rGO could serve as electrolyte storage micro-pools and transport channels, which could provide sufficient and timely electrolyte replenishment for ultrafast charging/discharging.

Question: What's the electrolyte?
Answer: NVPF@5% rGO
Dr Hongfei Li obtained his B.S. degree and M.S. degree in materials science and engineering from Central South University and Tsinghua University, respectively. After that, he received his PhD degree from City University of Hong Kong. Now, he is an associate professor at Songshan Lake Materials Laboratory. His research focuses on aqueous batteries, flexible and wearable energy storage devices, and polymer electrolytes. He has published more than 68 scientific papers with over 3800 total citations and an h-index of 36.

Question: What's the electrolyte?
Answer: polymer
We are able to clarify that the electrochemical doping of the polymer is still predominantly caused by the formation of ion pairs between charged polymer and PF6− anions, as DBSA itself causes irreversible doping of the polymer (Fig. 4). Fig. 4a shows the behaviour of DBSA in an electrochemical cell with no other salts present by exposing a P3HT thin film to 0.1 M DBSA in ACN electrolyte and measuring in situ ERRS. We observe the typical hole polaron signature in P3HT even at 0 V, indicating the ability of DBSA to chemically dope the polymer film when no other salts are present. We monitor the CC peak position as a function of oxidising potential and find the doping level has a minor dependence on applied bias indicated by the CC peak downshifting from 1425 cm−1 to 1417 cm−1 (Fig. 4b); the electric field causes more DBSA anions (dissociated from protons) to drift and penetrate into the P3HT film causing further doping. After discharge (0 V) the film is irreversibly doped and the CC peak position remains at 1417 cm−1 (green triangle Fig. 4a). Further evidence for irreversible p-type doping caused by DBSA is provided by changes in the UV-Vis absorbance spectra, HOMO level, and work function (see Fig. S2, ESI†). Thus, we elucidate that the mixed ionic electrolyte (with DBSA and TBA:PF6) causes reversible electrochemical doping of the polymer caused by the formation of ion pairs between charged polymer and PF6− anions. This suggests that the effect of DBSA in the mixed electrolyte is to modify the interaction between the polymer and the electrolyte allowing electrochemical doping at a lower voltage. DBSA has previously been used as a surfactant added to PEDOT:PSS formulations to improve wettability. We believe that DBSA could be having a similar effect on P3HT, interacting with the polymer and acting as a surfactant to enhance the strength of the interactions between the polymer and the electrolyte. In other words, DBSA may modulate the RED between the polymer and the solvent. We demonstrated the effect of RED between the solvent and the polymer on oxidation onset during cyclic voltammetry measurements: there is a lower RED between DCM and P3HT compared to ACN and P3HT, which results in a reduction in the oxidation onset of 0.28 V (Fig. 2). Thus, the RED between the polymer and the electrolyte solvent appears to influence the injection barrier into the film. By adding DBSA to the electrolyte, it may reduce the RED, thus causing a higher mass in the polymer film (solvent and ions), ultimately decreasing the injection barrier into the film.

Question: What's the electrolyte?
Answer: 0.1 M DBSA in ACN
We are able to clarify that the electrochemical doping of the polymer is still predominantly caused by the formation of ion pairs between charged polymer and PF6− anions, as DBSA itself causes irreversible doping of the polymer (Fig. 4). Fig. 4a shows the behaviour of DBSA in an electrochemical cell with no other salts present by exposing a P3HT thin film to 0.1 M DBSA in ACN electrolyte and measuring in situ ERRS. We observe the typical hole polaron signature in P3HT even at 0 V, indicating the ability of DBSA to chemically dope the polymer film when no other salts are present. We monitor the CC peak position as a function of oxidising potential and find the doping level has a minor dependence on applied bias indicated by the CC peak downshifting from 1425 cm−1 to 1417 cm−1 (Fig. 4b); the electric field causes more DBSA anions (dissociated from protons) to drift and penetrate into the P3HT film causing further doping. After discharge (0 V) the film is irreversibly doped and the CC peak position remains at 1417 cm−1 (green triangle Fig. 4a). Further evidence for irreversible p-type doping caused by DBSA is provided by changes in the UV-Vis absorbance spectra, HOMO level, and work function (see Fig. S2, ESI†). Thus, we elucidate that the mixed ionic electrolyte (with DBSA and TBA:PF6) causes reversible electrochemical doping of the polymer caused by the formation of ion pairs between charged polymer and PF6− anions. This suggests that the effect of DBSA in the mixed electrolyte is to modify the interaction between the polymer and the electrolyte allowing electrochemical doping at a lower voltage. DBSA has previously been used as a surfactant added to PEDOT:PSS formulations to improve wettability. We believe that DBSA could be having a similar effect on P3HT, interacting with the polymer and acting as a surfactant to enhance the strength of the interactions between the polymer and the electrolyte. In other words, DBSA may modulate the RED between the polymer and the solvent. We demonstrated the effect of RED between the solvent and the polymer on oxidation onset during cyclic voltammetry measurements: there is a lower RED between DCM and P3HT compared to ACN and P3HT, which results in a reduction in the oxidation onset of 0.28 V (Fig. 2). Thus, the RED between the polymer and the electrolyte solvent appears to influence the injection barrier into the film. By adding DBSA to the electrolyte, it may reduce the RED, thus causing a higher mass in the polymer film (solvent and ions), ultimately decreasing the injection barrier into the film.

Question: What's the electrolyte?
Answer: (with DBSA and TBA:PF6)
The cycle stability in terms of the charge capacity for the two kinds of films in the Li/Al-ion electrolyte was also evaluated as shown in Fig. 3a and b (details for the in situ measurement of both the charge capacity and the transmittance are provided in the ESI†). After 1000 cycles, the capacity retention was about 78% for the Ti-V2O5 film and 72% for the WO3 film. The cycle stability in terms of the electrochromic performance is obtained by monitoring the optical contrast between the colored and the bleached state of the films. As shown in Fig. 3c and d, after 1000 cycles, the Ti-V2O5 film still delivered a transmittance contrast of up to 24.8% at 400 nm, and for the WO3 film, a contrast up to 47.4% was delivered at 780 nm. These values show that 69.5% of the optical modulation can be retained for Ti-V2O5 and 65.4% can be retained for the WO3 film after 1000 cycles. As a comparison, the Al-ion electrolyte, which is commonly used in Al-based EES devices, was applied to replace the Li/Al-ion electrolyte. As shown in Fig. S6,† for both the Ti-V2O5 and the WO3 films, the optical contrast in the transmittance spectra drops rapidly within 100 cycles, indicating that the mixed ion electrolyte effectively promotes the cycle stability of the electrochromic films.

Question: What's the electrolyte?
Answer:  Li/Al-ion
The cycle stability in terms of the charge capacity for the two kinds of films in the Li/Al-ion electrolyte was also evaluated as shown in Fig. 3a and b (details for the in situ measurement of both the charge capacity and the transmittance are provided in the ESI†). After 1000 cycles, the capacity retention was about 78% for the Ti-V2O5 film and 72% for the WO3 film. The cycle stability in terms of the electrochromic performance is obtained by monitoring the optical contrast between the colored and the bleached state of the films. As shown in Fig. 3c and d, after 1000 cycles, the Ti-V2O5 film still delivered a transmittance contrast of up to 24.8% at 400 nm, and for the WO3 film, a contrast up to 47.4% was delivered at 780 nm. These values show that 69.5% of the optical modulation can be retained for Ti-V2O5 and 65.4% can be retained for the WO3 film after 1000 cycles. As a comparison, the Al-ion electrolyte, which is commonly used in Al-based EES devices, was applied to replace the Li/Al-ion electrolyte. As shown in Fig. S6,† for both the Ti-V2O5 and the WO3 films, the optical contrast in the transmittance spectra drops rapidly within 100 cycles, indicating that the mixed ion electrolyte effectively promotes the cycle stability of the electrochromic films.

Question: What's the electrolyte?
Answer:  Al-ion