milerssliu/battery-device-data-qa huggingface dataset:
In the context of reversibility, an excellent 1st cycle coulombic efficiency (CE) of ∼91% could be obtained with the MWCNT containing electrode, which is much higher than a CE of ∼78% recorded for the non-MWCNT containing counterpart (as reported in Section 3.3). Here, it may be mentioned that in another recently published study from our group (viz., ) addition of similarly functionalized MWCNTs to Na-titanate in the same way also enhanced the CE and cyclic stability in significant terms. In that study it was observed that the MWCNT network tends to uniformly ‘wrap’ the electrode-active particles due to favourable surface interaction, which, in turn, suppressed the occurrence of deleterious irreversible surface reactions with the electrolyte and, thus, improved the electrochemical performances. Even though looking more closely into such aspects here is beyond the scope of the presently reported work per se, it is not unlikely that the above mechanism may also be relevant to our Na-TM-oxide – MWCNT electrodes. On a slightly different note, a closer look at Fig. 3a, 7a and S9 (in the ESI†) indicates that the overpotential (or polarization) associated with the initiation of electrochemical desodiation gets lowered in the presence of MWCNTs. This may, in turn, be a manifestation of the improved conductivity bestowed by the MWCNT network, which assumes greater importance here due to the presence of d0 TM-ions in the concerned Na-TM-oxide.

Question: What's the electrolyte?
FEC and DMC were purchased from SoulBrain Corp. LiPF6 was purchased from BASF Corp. Li chips (450 μm) were purchased from MTI Corp. The baseline electrolyte is 1 M LiPF6 + DMC/FEC (v/v = 8/2). The high fluorine content can provide a relatively robust electrolyte/electrode interface toward aggressive chemistries under high potentials. The electrolyte used for the protection failure study was commercial carbonate electrolyte: 1 M LiPF6 + EC/EMC (v/v = 4/6). TDAC·PF6 crystal powder was dissolved in baseline electrolyte to fabricate 0.2 M TDAC electrolyte. The NCA cathode, LMO cathode and graphite anode were composed of the active material, polyvinylidene fluoride (PVDF) binder and Super C carbon in a mass ratio of 90:5:5. The areal capacity of the NCA cathode, LMO cathode and graphite anode is 2.2 mA h cm−2. The NCA cathode and silicon–graphene (Si–C) anode sheets, with an areal capacity of ∼3 mA h cm−2, were kindly provided by NanoGraf Corp. The formulation of the anode sheet was the Si–C active material (mass ratio of 45:55), PVDF binder and Super C carbon in a mass ratio of 75:5:20. The loadings of the NCA cathode and Si–C anode were ∼18–19 mg cm−2 and ∼3–4 mg cm−2, respectively. All electrode sheets were dried under vacuum at 80 °C overnight before use.

Question: What's the cathode?
Answer: LMO
FEC and DMC were purchased from SoulBrain Corp. LiPF6 was purchased from BASF Corp. Li chips (450 μm) were purchased from MTI Corp. The baseline electrolyte is 1 M LiPF6 + DMC/FEC (v/v = 8/2). The high fluorine content can provide a relatively robust electrolyte/electrode interface toward aggressive chemistries under high potentials. The electrolyte used for the protection failure study was commercial carbonate electrolyte: 1 M LiPF6 + EC/EMC (v/v = 4/6). TDAC·PF6 crystal powder was dissolved in baseline electrolyte to fabricate 0.2 M TDAC electrolyte. The NCA cathode, LMO cathode and graphite anode were composed of the active material, polyvinylidene fluoride (PVDF) binder and Super C carbon in a mass ratio of 90:5:5. The areal capacity of the NCA cathode, LMO cathode and graphite anode is 2.2 mA h cm−2. The NCA cathode and silicon–graphene (Si–C) anode sheets, with an areal capacity of ∼3 mA h cm−2, were kindly provided by NanoGraf Corp. The formulation of the anode sheet was the Si–C active material (mass ratio of 45:55), PVDF binder and Super C carbon in a mass ratio of 75:5:20. The loadings of the NCA cathode and Si–C anode were ∼18–19 mg cm−2 and ∼3–4 mg cm−2, respectively. All electrode sheets were dried under vacuum at 80 °C overnight before use.

Question: What's the anode?
Answer: graphite
FEC and DMC were purchased from SoulBrain Corp. LiPF6 was purchased from BASF Corp. Li chips (450 μm) were purchased from MTI Corp. The baseline electrolyte is 1 M LiPF6 + DMC/FEC (v/v = 8/2). The high fluorine content can provide a relatively robust electrolyte/electrode interface toward aggressive chemistries under high potentials. The electrolyte used for the protection failure study was commercial carbonate electrolyte: 1 M LiPF6 + EC/EMC (v/v = 4/6). TDAC·PF6 crystal powder was dissolved in baseline electrolyte to fabricate 0.2 M TDAC electrolyte. The NCA cathode, LMO cathode and graphite anode were composed of the active material, polyvinylidene fluoride (PVDF) binder and Super C carbon in a mass ratio of 90:5:5. The areal capacity of the NCA cathode, LMO cathode and graphite anode is 2.2 mA h cm−2. The NCA cathode and silicon–graphene (Si–C) anode sheets, with an areal capacity of ∼3 mA h cm−2, were kindly provided by NanoGraf Corp. The formulation of the anode sheet was the Si–C active material (mass ratio of 45:55), PVDF binder and Super C carbon in a mass ratio of 75:5:20. The loadings of the NCA cathode and Si–C anode were ∼18–19 mg cm−2 and ∼3–4 mg cm−2, respectively. All electrode sheets were dried under vacuum at 80 °C overnight before use.

Question: What's the electrolyte?
Answer: 1 M LiPF6 + DMC/FEC
FEC and DMC were purchased from SoulBrain Corp. LiPF6 was purchased from BASF Corp. Li chips (450 μm) were purchased from MTI Corp. The baseline electrolyte is 1 M LiPF6 + DMC/FEC (v/v = 8/2). The high fluorine content can provide a relatively robust electrolyte/electrode interface toward aggressive chemistries under high potentials. The electrolyte used for the protection failure study was commercial carbonate electrolyte: 1 M LiPF6 + EC/EMC (v/v = 4/6). TDAC·PF6 crystal powder was dissolved in baseline electrolyte to fabricate 0.2 M TDAC electrolyte. The NCA cathode, LMO cathode and graphite anode were composed of the active material, polyvinylidene fluoride (PVDF) binder and Super C carbon in a mass ratio of 90:5:5. The areal capacity of the NCA cathode, LMO cathode and graphite anode is 2.2 mA h cm−2. The NCA cathode and silicon–graphene (Si–C) anode sheets, with an areal capacity of ∼3 mA h cm−2, were kindly provided by NanoGraf Corp. The formulation of the anode sheet was the Si–C active material (mass ratio of 45:55), PVDF binder and Super C carbon in a mass ratio of 75:5:20. The loadings of the NCA cathode and Si–C anode were ∼18–19 mg cm−2 and ∼3–4 mg cm−2, respectively. All electrode sheets were dried under vacuum at 80 °C overnight before use.

Question: What's the cathode?
Answer: NCA
FEC and DMC were purchased from SoulBrain Corp. LiPF6 was purchased from BASF Corp. Li chips (450 μm) were purchased from MTI Corp. The baseline electrolyte is 1 M LiPF6 + DMC/FEC (v/v = 8/2). The high fluorine content can provide a relatively robust electrolyte/electrode interface toward aggressive chemistries under high potentials. The electrolyte used for the protection failure study was commercial carbonate electrolyte: 1 M LiPF6 + EC/EMC (v/v = 4/6). TDAC·PF6 crystal powder was dissolved in baseline electrolyte to fabricate 0.2 M TDAC electrolyte. The NCA cathode, LMO cathode and graphite anode were composed of the active material, polyvinylidene fluoride (PVDF) binder and Super C carbon in a mass ratio of 90:5:5. The areal capacity of the NCA cathode, LMO cathode and graphite anode is 2.2 mA h cm−2. The NCA cathode and silicon–graphene (Si–C) anode sheets, with an areal capacity of ∼3 mA h cm−2, were kindly provided by NanoGraf Corp. The formulation of the anode sheet was the Si–C active material (mass ratio of 45:55), PVDF binder and Super C carbon in a mass ratio of 75:5:20. The loadings of the NCA cathode and Si–C anode were ∼18–19 mg cm−2 and ∼3–4 mg cm−2, respectively. All electrode sheets were dried under vacuum at 80 °C overnight before use.

Question: What's the anode?
Answer: silicon–graphene (Si–C)
FEC and DMC were purchased from SoulBrain Corp. LiPF6 was purchased from BASF Corp. Li chips (450 μm) were purchased from MTI Corp. The baseline electrolyte is 1 M LiPF6 + DMC/FEC (v/v = 8/2). The high fluorine content can provide a relatively robust electrolyte/electrode interface toward aggressive chemistries under high potentials. The electrolyte used for the protection failure study was commercial carbonate electrolyte: 1 M LiPF6 + EC/EMC (v/v = 4/6). TDAC·PF6 crystal powder was dissolved in baseline electrolyte to fabricate 0.2 M TDAC electrolyte. The NCA cathode, LMO cathode and graphite anode were composed of the active material, polyvinylidene fluoride (PVDF) binder and Super C carbon in a mass ratio of 90:5:5. The areal capacity of the NCA cathode, LMO cathode and graphite anode is 2.2 mA h cm−2. The NCA cathode and silicon–graphene (Si–C) anode sheets, with an areal capacity of ∼3 mA h cm−2, were kindly provided by NanoGraf Corp. The formulation of the anode sheet was the Si–C active material (mass ratio of 45:55), PVDF binder and Super C carbon in a mass ratio of 75:5:20. The loadings of the NCA cathode and Si–C anode were ∼18–19 mg cm−2 and ∼3–4 mg cm−2, respectively. All electrode sheets were dried under vacuum at 80 °C overnight before use.

Question: What's the electrolyte?
Answer: 0.2 M TDAC
In summary, we demonstrated the use of a multicomponent electrolyte containing sodium perchlorate, urea, N,N-dimethylformamide (DMF) and water, enabling us to immensely decrease the amount of water, forming a complex solvent sheath and a uniform SEI layer composed of complexes with inorganic salt Na2CO3 and other organic components between the interface of the NTP anode and electrolyte. Such an electrolyte provides a voltage window up to 2.8 V and ensures the feasibility of stable and reversible operation of a NVP/NTP sodium ion battery. This battery exhibits an excellent flat voltage platform of about 1.2 V and achieves 86% capacity retention after 100 cycles at the 10C rate. Simultaneously, a NiHCF//NTP full cell with the MCAE displays 80% capacity retention after 2000 cycles at 2C rate. In addition, this MCAE displays high safety, a wide operating temperature range (−50 °C to 50 °C) and high ionic conductivity because of the roles of urea and DMF additives. And above all, the fluorine-free MCAE makes the battery much safer and more environmentally friendly than the existing battery systems with highly concentrated aqueous electrolytes. Meanwhile, we provide a new perspective that can be expanded to other systems of aqueous sodium-ion full cells, which promotes the application of safe, environmentally friendly and stable AISBs for large-scale energy storage.

Question: What's the anode?
Answer: NTP
In summary, we demonstrated the use of a multicomponent electrolyte containing sodium perchlorate, urea, N,N-dimethylformamide (DMF) and water, enabling us to immensely decrease the amount of water, forming a complex solvent sheath and a uniform SEI layer composed of complexes with inorganic salt Na2CO3 and other organic components between the interface of the NTP anode and electrolyte. Such an electrolyte provides a voltage window up to 2.8 V and ensures the feasibility of stable and reversible operation of a NVP/NTP sodium ion battery. This battery exhibits an excellent flat voltage platform of about 1.2 V and achieves 86% capacity retention after 100 cycles at the 10C rate. Simultaneously, a NiHCF//NTP full cell with the MCAE displays 80% capacity retention after 2000 cycles at 2C rate. In addition, this MCAE displays high safety, a wide operating temperature range (−50 °C to 50 °C) and high ionic conductivity because of the roles of urea and DMF additives. And above all, the fluorine-free MCAE makes the battery much safer and more environmentally friendly than the existing battery systems with highly concentrated aqueous electrolytes. Meanwhile, we provide a new perspective that can be expanded to other systems of aqueous sodium-ion full cells, which promotes the application of safe, environmentally friendly and stable AISBs for large-scale energy storage.

Question: What's the electrolyte?
Answer: sodium perchlorate, urea, N,N-dimethylformamide (DMF) and wate
The electrochemical properties of the prepared α-MnS@NS-C samples were evaluated with lithium metal as the reference electrode. For electrochemical measurements, the obtained α-MnS@NS-C material was mixed with carbon black (SuperP) and polyacrylic acid binder in the stoichiometric ratio of 80:10:10. This slurry was coated on Cu foil and vacuum dried at 120 °C for 12 h to form the anode. An active material loading of 1.5 mg cm−2 was used. A 2032-coin type cell comprising a cathode and lithium metal anode separated by a polymer membrane (Celgard 2400) and a glass fiber (Whatman GF/B) was fabricated in an Ar-filled glove box and aged for 12 h before electrochemical measurements. The electrolyte employed was a 1:1 mixture of ethylene carbonate and dimethyl carbonate containing 1 M LiPF6. Galvanostatic measurements were performed on test coin cells using a programmable battery tester (BTS-2004H, Nagano, Japan) over the potential range of 0.01–3.0 V versus Li+/Li. Cyclic voltammetry (CV) measurements were performed using a Biologic instrument within the voltage range of 0.01–3.0 V and a scan rate of 0.1–1.0 mV s−1.

Question: What's the cathode?
The electrochemical properties of the prepared α-MnS@NS-C samples were evaluated with lithium metal as the reference electrode. For electrochemical measurements, the obtained α-MnS@NS-C material was mixed with carbon black (SuperP) and polyacrylic acid binder in the stoichiometric ratio of 80:10:10. This slurry was coated on Cu foil and vacuum dried at 120 °C for 12 h to form the anode. An active material loading of 1.5 mg cm−2 was used. A 2032-coin type cell comprising a cathode and lithium metal anode separated by a polymer membrane (Celgard 2400) and a glass fiber (Whatman GF/B) was fabricated in an Ar-filled glove box and aged for 12 h before electrochemical measurements. The electrolyte employed was a 1:1 mixture of ethylene carbonate and dimethyl carbonate containing 1 M LiPF6. Galvanostatic measurements were performed on test coin cells using a programmable battery tester (BTS-2004H, Nagano, Japan) over the potential range of 0.01–3.0 V versus Li+/Li. Cyclic voltammetry (CV) measurements were performed using a Biologic instrument within the voltage range of 0.01–3.0 V and a scan rate of 0.1–1.0 mV s−1.

Question: What's the anode?
Answer: lithium metal
The electrochemical properties of the prepared α-MnS@NS-C samples were evaluated with lithium metal as the reference electrode. For electrochemical measurements, the obtained α-MnS@NS-C material was mixed with carbon black (SuperP) and polyacrylic acid binder in the stoichiometric ratio of 80:10:10. This slurry was coated on Cu foil and vacuum dried at 120 °C for 12 h to form the anode. An active material loading of 1.5 mg cm−2 was used. A 2032-coin type cell comprising a cathode and lithium metal anode separated by a polymer membrane (Celgard 2400) and a glass fiber (Whatman GF/B) was fabricated in an Ar-filled glove box and aged for 12 h before electrochemical measurements. The electrolyte employed was a 1:1 mixture of ethylene carbonate and dimethyl carbonate containing 1 M LiPF6. Galvanostatic measurements were performed on test coin cells using a programmable battery tester (BTS-2004H, Nagano, Japan) over the potential range of 0.01–3.0 V versus Li+/Li. Cyclic voltammetry (CV) measurements were performed using a Biologic instrument within the voltage range of 0.01–3.0 V and a scan rate of 0.1–1.0 mV s−1.

Question: What's the electrolyte?
Answer: 1:1 mixture of ethylene carbonate and dimethyl carbonate containing 1 M LiPF6
Fig. 1a schematically shows the composition of the light-assisted Li–CO2 battery, which consisted of a Li anode, a non-aqueous electrolyte, a separator, and a cathode with the photo-electro-catalyst. Upon discharging under illumination (Fig. 1b), the photocatalyst is excited to generate holes and electrons after absorbing photons. Since the conduction band potential (VCB) of the photocatalyst is more negative than the standard redox potential of 2.8 V, photoexcited electrons could reduce CO2 by a photocatalytic reaction. Notably, the solar light provides significant energy for CO2 reduction in sharp contrast with the conventional Li–CO2 battery, in which the carbon dioxide reduction reaction (CO2RR) process is driven by the electrocatalytic reaction. Meanwhile, photoexcited holes capture the electrons from the Li anode through the external circuit due to the more positive valence band potential (VVB) than 2.8 V, ensuring the continuous supply of photoexcited electrons for the CO2RR process. During the charging process (Fig. 1c), the inverse reaction 4Li + 3CO2 → 2Li2CO3 + C is promoted by the photoexcited holes on the cathode on account of the positive VB position compared with 2.8 V. Simultaneously, the photoexcited electrons transfer to the anode through the external circuit to reduce Li+ to Li metal. In this photoassisted charging process, the photovoltage generated on the photo-catalyst is utilized to compensate the charging potential of the Li–CO2 battery.

Question: What's the cathode?
Fig. 1a schematically shows the composition of the light-assisted Li–CO2 battery, which consisted of a Li anode, a non-aqueous electrolyte, a separator, and a cathode with the photo-electro-catalyst. Upon discharging under illumination (Fig. 1b), the photocatalyst is excited to generate holes and electrons after absorbing photons. Since the conduction band potential (VCB) of the photocatalyst is more negative than the standard redox potential of 2.8 V, photoexcited electrons could reduce CO2 by a photocatalytic reaction. Notably, the solar light provides significant energy for CO2 reduction in sharp contrast with the conventional Li–CO2 battery, in which the carbon dioxide reduction reaction (CO2RR) process is driven by the electrocatalytic reaction. Meanwhile, photoexcited holes capture the electrons from the Li anode through the external circuit due to the more positive valence band potential (VVB) than 2.8 V, ensuring the continuous supply of photoexcited electrons for the CO2RR process. During the charging process (Fig. 1c), the inverse reaction 4Li + 3CO2 → 2Li2CO3 + C is promoted by the photoexcited holes on the cathode on account of the positive VB position compared with 2.8 V. Simultaneously, the photoexcited electrons transfer to the anode through the external circuit to reduce Li+ to Li metal. In this photoassisted charging process, the photovoltage generated on the photo-catalyst is utilized to compensate the charging potential of the Li–CO2 battery.

Question: What's the anode?
Answer: Li
Fig. 1a schematically shows the composition of the light-assisted Li–CO2 battery, which consisted of a Li anode, a non-aqueous electrolyte, a separator, and a cathode with the photo-electro-catalyst. Upon discharging under illumination (Fig. 1b), the photocatalyst is excited to generate holes and electrons after absorbing photons. Since the conduction band potential (VCB) of the photocatalyst is more negative than the standard redox potential of 2.8 V, photoexcited electrons could reduce CO2 by a photocatalytic reaction. Notably, the solar light provides significant energy for CO2 reduction in sharp contrast with the conventional Li–CO2 battery, in which the carbon dioxide reduction reaction (CO2RR) process is driven by the electrocatalytic reaction. Meanwhile, photoexcited holes capture the electrons from the Li anode through the external circuit due to the more positive valence band potential (VVB) than 2.8 V, ensuring the continuous supply of photoexcited electrons for the CO2RR process. During the charging process (Fig. 1c), the inverse reaction 4Li + 3CO2 → 2Li2CO3 + C is promoted by the photoexcited holes on the cathode on account of the positive VB position compared with 2.8 V. Simultaneously, the photoexcited electrons transfer to the anode through the external circuit to reduce Li+ to Li metal. In this photoassisted charging process, the photovoltage generated on the photo-catalyst is utilized to compensate the charging potential of the Li–CO2 battery.

Question: What's the electrolyte?
The energy and power of all the cells are also compared in the form of Ragone plots (i.e., the plots of specific energy against effective power density), as shown in Fig. 7f. All the capacitor cells show a standard variation of Ragone plots, which are generally observed for the power sources like supercapacitors. The effect of incorporating redox additives (DPA/KI, individually or dual) in the electrolyte component can be directly observed on the energy and power of the capacitor cells. It may be noticed that the enhancement in specific energy due to the incorporation of redox additives has been observed for each value of power density (Fig. 7f). The optimum value of Esp is found to be ∼73 W h kg−1 at a Peff of ∼568 W kg−1 for Cell#4 (with the redox-active GPE containing dual redox additives). The high specific energy of this carbon supercapacitor is not only due to high specific capacitance owing to dual redox activity at the interfaces (according to Scheme (3), mentioned above), it is also due to relatively high operating voltage window (∼2.5 V) of electrochemically stable IL-incorporated, non-aqueous gel polymer films as electrolytes. The specific energy values of the present capacitor cell (Cell#4) are substantially higher than or equivalent to that of many reported carbon supercapacitors based on redox-active non-aqueous electrolytes including GPEs. A comparison of the present system with similar devices, reported in the literature, is given in Table 3.

Question: What's the electrolyte?
Answer: non-aqueous gel polymer films