batterydata/battery-device-data-qa huggingface dataset:
To examine the catalytic and capture property of 1T MoS2 NDs in a working Li–S cell, MoS2 ND/porous carbon/Li2S6 cathodes were prepared and subjected to synchrotron in situ XRD and in situ EIS characterizations. Fig. 4 shows the contour plot of the in situ XRD patterns collected during the first two cycles. Before discharging, no crystalline peaks were observed, confirming the high purity of the polysulfide catholyte and the low content of MoS2 NDs. When the cell was discharged to the plateau at 2.1 V, peaks referring to the (111) and (200) planes of cubic Li2S (PDF No. 023-0369, marked with a black dashed-line) appeared and reached their maximum intensity at the end of lithiation (bottom of Fig. 4). Upon charging, the intensity of Li2S decreased gradually, followed with no discernible XRD peaks and then the generation of monoclinic S8 (PDF No. 071-0137, marked with white dashed-lines), illustrating the solid (Li2S)–liquid (polysulfides)–solid (S8) reactions during the charging process. During the 2nd discharge/charge, reversible transitions between sulfur and Li2S were observed. When we compare the current in situ XRD results with peer studies, two findings can be extracted. First, MoS2 NDs propel the formation of Li2S crystals. Nelson et al. and Yang et al. both argued that the sluggish kinetics for solid (Li2S2)–solid (Li2S) conversion prevents Li2S formation upon the full discharge of sulfur/carbon electrodes, resulting in undetectable Li2S crystals during in situ XRD studies. The incomplete reduction accounted for the deficient sulfur utilization and low reversible capacities. Fortunately, the powerful MoS2 ND catalysts enabled the reversible formation of crystalline Li2S in our operando XRD studies. Second, Ye et al. reported that the poor catalytic capability of MoN led to occasioned residual S8 XRD peaks for the MoN/sulfur electrode after full discharging, which was also observed for conventional 2H MoS2 flakes-modified porous carbon/Li2S6 cathodes in this work (Fig. S9, ESI†). In contrast, no residual sulfur/Li2S crystals were observed for MoS2 ND/porous carbon/Li2S6 after full discharging/charging, respectively, again indicating the high catalytic property of the 1T MoS2 NDs.

Question: What's the cathode?
Answer: MoS2 ND/porous carbon/Li2S6

Question: What's the cathode?
Answer: porous carbon/Li2S6
Finally, the versatility in designing nickel nanomesh with different pore sizes, porosities and surface areas can be used to further optimize the structure of nanomesh cathodes for either very high capacities or yet a higher rate performance. For example, in the electrodes prepared in this work, the 3D current collector occupied 24% of the electrode volume. Although this is in the normal range for 3D cathodes (that have up to 40% volume lost to the current collector, Table S3†), it leaves room for improvement. Using nanomesh with yet a higher porosity (currently, up to 89%) may allow packing more active material into the structure and further increasing its volumetric capacity. If the nanomesh is designed with a proper combination of the nanowire diameter and spacing, the high surface area of the current collector can be preserved even for such highly porous nanomesh, maintaining its benefits in high utilization of active Li-ion materials. Because of its customizable structure, nanomesh can also be used to study the fundamental effects of a 3D structure on the properties of Li-ion electrodes. Knowing that nanomesh can also be fabricated as free-standing and flexible foil, the current work paves the way for future free-standing and stackable nanomesh-based cathodes. This, combined with the upscalable and generally feasible method of their fabrication, can make the cathodes attractive for practical application in high capacity and fast charging Li-ion batteries.

Question: What's the cathode?
Answer: nanomesh

Question: What's the cathode?
Answer:  nanomesh-based
Similarly, the cycled S-C(PAN) electrodes paired with bare and coated LMO cathodes were investigated by XPS to confirm the SEI layer components and whether there was dissolved manganese deposited on the anode surface. Fig. 7 shows the XPS spectra of the Mn 2p and O 1s peaks on the S-C(PAN) anodes cycled at 25 °C (bare LMO and LMO-30 min) and 55 °C (LMO-30 min) after 100 cycles using 0.4C-rate. Fig. 7a shows the deposition of manganese on the anode surface when a cell was cycled using a bare LMO cathode and it displays two peaks at 640.1 (Mn2+) and 641.3 eV (Mn3+) for Mn 2p3/2. The decomposition of organic compounds from the electrolyte devastates the original SEI layer and the formation of a new SEI layer on the negative electrode surface in the form of MnxOy occurs. In the case of the LMO-30 min cathode, as shown in Fig. 7b and c, the deposition of manganese on the cycled S-C(PAN) electrode was hardly observed. In addition to XPS, EDS analysis and elemental mapping were also performed. No manganese content was detected on the anode surface when the cell was cycled with the LMO-30 min cathode at 25 °C (Fig. S6†) and LMO-30 min cathode at 55 °C (Fig. S7†). However, the cycled S-C(PAN) anode paired with bare LMO shows Mn distribution in Fig. S8.† As mentioned above, the PVDF@LGLZNO fibrous film protects the cathode and reduces the direct contact of the LMO cathode and the electrolyte. The peak of Mn was absent in the PVDF@LGLZNO coated LMO cathodes. DFT calculation further suggests that the dissolved manganese ion can be adsorbed on the garnet surface, whereby the adsorption energy of Mn2+ on the surface of the garnet was calculated as −53.067 kJ mol−1. Details about the estimation can be referred to in the ESI and Fig. S9.†

Question: What's the anode?
Answer: S-C(PAN)

Question: What's the anode?
Answer: S-C(PAN)
Liquid rechargeable Zn–air batteries were assembled with a homemade cell. A zinc sheet (purity 99.9 wt%) was used as the anode, which was polished with sandpaper before use. A mixed solution of 6 M KOH and 0.2 M Zn(Ac)2 was used as the electrolyte. The air cathode was composed of three layers, a catalyst layer, a nickel foam layer and a gas diffusion layer. The catalytic layer was fabricated by homogeneously mixing the NCAG/Fe–Co catalyst, acetylene black, PTFE (60 wt%) at the mass ratio of 6:1:3. The nickel foam was treated with 0.2 M HCl, water and ethanol for 20 min, successively, and then vacuum dried at 60 °C before use. The three layers were compressed with a roll press to obtain the cathode, which was then vacuum dried at 60 °C for 3 h.

Question: What's the cathode?

Question: What's the anode?
Answer: zinc sheet

Question: What's the electrolyte?
Answer: A mixed solution of 6 M KOH and 0.2 M Zn(Ac)2
The non-aqueous gel polymer electrolyte (GPE) with dual redox additives was prepared by the “solution-cast” technique. Solid pellets of the host polymer PVdF-HFP (1 g) were put in 20 ml acetone and allowed to dissolve properly at room temperature by continuous stirring on a magnetic stirrer for 12 hours. Thereafter, 4 g IL was added in the polymer solution and stirred for another 12 hours. Redox additives (0.04 g KI) and (0.04 g DPA) were added in the PVdF-HFP/IL solution and stirred for further 12 hours at room temperature to obtain a homogeneous and clear solution. The solution was then poured in a glass petri dish and the common solvent acetone was allowed to evaporate slowly at room temperature. Upon complete evaporation of acetone, a free-standing, flexible and mechanically stable GPE film was obtained. The thickness of the dual redox-active GPE film was ∼400 μm. For the comparison, GPEs of compositions PVdF-HFP:IL (20:80 w/w), and PVdF-HFP/IL/DPA and PVdF-HFP/IL/KI with different amounts of redox additives were also prepared by the same procedure, as described above. These GPEs were stored in a dry atmosphere to avoid moisture adsorption. These GPE films were characterized by electrochemical impedance spectroscopy (EIS), linear sweep voltammetry (LSV), and thermogravimetric analysis (TGA). The room temperature ionic conductivity of all the GPEs was measured by EIS in the frequency range from 105 Hz to 1 Hz. The electrochemical stability window (ESW) for each GPE film was measured by LSV at a scan rate of 5 mV s−1. EIS and LSV were performed on an electrochemical analyzer (CHI660E, CH Instruments, USA). TGA was performed on a Perkin Elmer (USA) TGA-7 system from room temperature to 600 °C at a heating rate of 10 °C min−1 in a N2 atmosphere.

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

Question: What's the electrolyte?
Answer: GPE
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

Question: What's the anode?
Answer: graphite

Question: What's the electrolyte?
Answer: 1 M LiPF6 + DMC/FEC

Question: What's the cathode?
Answer: NCA

Question: What's the anode?
Answer: silicon–graphene (Si–C)

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

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?

Question: What's the anode?
Answer: lithium metal

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?

Question: What's the anode?
Answer: Li

Question: What's the electrolyte?

Question: What's the anode?
Answer: Li
Polyanionic materials are a series of compounds containing polyhedral anionic structural units, which are linked to construct a three-dimensional network structure by strong covalent bonds. The unique structure endows the compounds with a stable crystal structure, moderate capacity, high operating voltage, and safety. Among them, monoclinic LiV2(PO4)3 (discharges to be Li3V2(PO4)3) is one of the most attractive cathode materials for primary batteries, which has stable voltage plateaus between 3.0 V and 4.3 V (vs. Li+/Li) and a suitable theoretical specific capacity (133 mA h g−1) corresponding to the insertion of two Li ions per formula unit. Most importantly, the unique NASICON structure of Li3V2(PO4)3 facilitates Li+ conduction and delivers faster Li+ diffusion kinetics when compared with traditional cathode materials such as LiFePO4, LiCoO2, and LiNi1/3Co1/3Mn1/3O2, ensuring superior rate capability and low-temperature performance. Thus, LiV2(PO4)3 has great potential for application as a cathode material for lithium primary batteries. For practical application, the shelf life of the Li/LiV2(PO4)3 batteries should be long enough; this means that the self-discharge rate should be as low as possible. Since the Li/LiV2(PO4)3 primary battery possesses a high open-circuit voltage (OCV) of about 4.1 V, the side reactions among electrode materials, electrolyte, and even current collectors can severely affect the shelf life of these batteries. In addition, the corrosion of the current collector leads to self-discharge. Therefore, stabilizing the interface between the electrode and electrolyte is essential.

Question: What's the cathode?
Answer: monoclinic LiV2(PO4)3 (discharges to be Li3V2(PO4)3

Question: What's the electrolyte?

Question: What's the cathode?
Answer: LiFePO4, LiCoO2, and LiNi1/3Co1/3Mn1/3O2
NaxTMO2 type [TM: transition metal(s)] ‘layered’ oxides, having an initial Na-content (x) of ∼1 (i.e., ‘O3’), are important as potential cathode materials for upcoming Na-ion battery systems. However, among other problems (viz., phase transformations during Na-removal/insertion, TM-dissolution etc.), such oxides suffer from severe instability against hydration in a generic sense, which in turn, negatively impacts the stability, electrochemical performances and environment/health friendliness. Against this backdrop, we have designed a composition (viz., combination of TM-/non-TM-ions) to address the aforementioned problems, in particular, air/water-instability. Partial/complete substitution of Ti-ions for Mn-ions eliminated the presence of Mn3+ (which dissolves in electrolyte) at the particle surface, suppressed the increment in impedance (as well as voltage hysteresis) during electrochemical cycling and, thus, significantly improved cyclic stability. More importantly, the air/water-stability improved drastically, such that no phase/structural change occurred even after 40 days of air-exposure and 12 h of stirring in water, unlike for predominately Mn-ion containing counterparts, which progressively evolved O′3 and P3 phases. In fact, water-stability enabled the usage of environment/health friendly, as well as less expensive, ‘aqueous-binder’ (viz., Na-alginate) and water (as solvent) for electrode preparation. The as-developed environment/health friendly ‘aqueous-processed’ electrode also exhibits excellent long-term cyclic stability, with capacity retention being ∼82% after 100 cycles (∼60% after 500 cycles and ∼56% after 750 cycles) at C/5, along with just ∼4% capacity fade over the last 250 cycles investigated (viz., cycles 500–750). Such an elimination of requirements for toxic/hazardous-cum-expensive ‘non-aqueous’ solvents/binders for electrode preparation and the associated learning, in terms of suitable combinations of TM-/non-TM-ions for these oxides in the pursuit of desired structural features, are significant steps towards the development of alkali metal-ion batteries in general.

Question: What's the cathode?
Answer: NaxTMO2

Question: What's the electrolyte?
Although tremendous efforts have resulted in the great advances in recent years, O3-type layered oxide cathode materials have been plagued by the issue of poor thermal stability and structural stability against a humid atmosphere, which are favorable properties for practical application. To confirm the practical acceptability, we first checked the thermal stability and air-stability of the Na0.98Ca0.01[Ni0.5Mn0.5]O2 cathode by comparing it with the Na[Ni0.5Mn0.5]O2 cathode. Differential scanning calorimetry (DSC) was performed to observe the exothermic reactions of the deeply de-sodiated electrodes (highly unstable state) collected from cells charged to 4.3 V (vs. Na/Na+) after the first cycle. The results are plotted in Fig. S15,† showing both onset temperature of the exothermic reactions and the total specific heat generation. Although a similar amount of Na+ ions (according to charge capacities) was extracted from the crystal structure, the thermal reaction between NaxCa0.01[Ni0.5Mn0.5]O2 and Nax[Ni0.5Mn0.5]O2 (x is close to 0) cathodes was different. In contrast, the Nax[Ni0.5Mn0.5]O2 electrode displayed an exothermic peak at 254.1 °C with a heat generation of 634.5 J g−1, the NaxCa0.01[Ni0.5Mn0.5]O2 electrode showed a lower heat generation of 352 J g−1 and an exothermic peak at 258.9 °C. It should be noted that the thermal reaction is related to the evolution of oxygen from the crystal structure because the oxygen released from the cathode materials can react with the electrolyte solution and undergo a redox reaction. Therefore, it is strongly believed that the improved thermal stability of the Ca-substituted cathode likely resulted from the strong interaction of immobile Ca2+ with O2−, which suppresses the rate of release of thermal oxygen from the highly oxidized cathode material.

Question: What's the cathode?
Answer: O3-type layered oxide

Question: What's the electrolyte?

Question: What's the cathode?
Answer: Na0.98Ca0.01[Ni0.5Mn0.5]O2
On the other hand, the HER and OER are the two half-reactions involved in electrocatalytic water splitting. These hydrogen-based and oxygen-based alkaline electrochemical reactions are often hindered by sluggish kinetics, which leads to a large overpotential and low round-trip efficiency. Enormous effort has been devoted to the development of highly efficient electrocatalysts for the HER and OER based on the structure–activity relationship, to increase the reaction rate and efficiency of the total system. Accordingly, Liu et al. reported AuPtPdRhRu alloy nanoparticles for HER application by an ultrasonication-assisted wet chemical method (Fig. 5a and b). The as-synthesized quinary AuPtPdRhRu nanoparticles on carbon (AuPtPdRhRu/C), whose average diameter is 2.6 ± 0.3 nm, exhibited excellent HER activity and durability in a 1.0 M KOH electrolyte. The required overpotential of AuPtPdRhRu/C to drive a current density of −30 mA cm−2 was 190 mV, which is smaller than those of quaternary AuPtPdRh/C (260 mV) and ternary AuPtRh/C (600 mV) catalysts. AuPtPdRhRu/C exhibited a lower Tafel slope of 62 mV dec−1 compared to AuPtPdRh/C (91 mV dec−1), AuPtPd/C (177 mV dec−1), and benchmark Pt/C (77 mV dec−1) catalysts, indicating its superior activity toward the alkaline HER. Moreover, AuPtPdRhRu/C exhibited stable electrocatalytic performance over 8 h, verified by chronopotentiometry at a current density of 100 mA cm−2. Likewise, Qiu et al. reported noble-metal free nanoporous HEA catalysts for the OER under alkaline conditions. Quinary nanoporous NiCoFeAlX (np-NiCoFeAlX, X = V, Cr, Mn, Cu, Zr, Nb, Mo) and senary np-MoCuNiCoFeAl catalysts were fabricated by a mechanical alloying and chemical dealloying strategy. Among the catalysts, np-MoNiCoFeAl exhibited the lowest OER overpotential (240 mV) to drive a current density of 10 mA cm−2 in a 1.0 M KOH electrolyte. Moreover, the np-MoNiCoFeAl catalyst also showed a smaller Tafel slope of 46 mV dec−1, compared to ternary np-NiFeAl (62 mV dec−1) and quaternary np-NiCoFeAl (61 mV dec−1). Moreover, the quinary np-MoNiCoFeAl exhibited high durability compared to ternary and quaternary catalysts, and retained more than 95% of its initial activity after 2000 potential cycles. Due to the oxidative potential under OER conditions, the surface of np-MoNiCoFeAl might undergo oxidation, forming surface oxides on the HEA surfaces. After a chronopotentiometry test at 20 mA cm−2 for 50 h, however, the five elements were still uniformly distributed in np-MoNiCoFeAl, forming a high-entropy-oxide (HEO) skin that exhibits high-entropy driven stability.

Question: What's the cathode?
Answer: 1.0 M KOH

Question: What's the cathode?
Answer: 1.0 M KOH