batterydata/battery-device-data-qa huggingface dataset:
Li and co-authors applied PTCDA-derived polymer P10 as the anode for aqueous K-ion batteries. Saturated solutions of K2SO4 (∼0.69 M) or KNO3 (∼3.75 M) were tested as the electrolytes. The potassium nitrate solution enabled better rate capabilities with P10 as the active material, owing to the higher conductivity. Particularly, ∼90 mA h g−1 was delivered at 5.4 A g−1, which was about 70% of the value achieved at 0.36 A g−1. A full cell with the potassium hexacyanoferrate cathode had an energy density of 24.2 W h kg−1 (per mass of both electrodes), could reach a high power of 2.08 kW kg−1, and retained 74% of the capacity after 300 cycles.

Question: What's the cathode?
Answer: potassium hexacyanoferrate

Question: What's the anode?
Answer: PTCDA-derived polymer P10

Question: What's the electrolyte?
Answer: K2SO4 (∼0.69 M) or KNO3 (∼3.75 M)
Electrolytic water splitting in an electrochemical cell can produce both hydrogen and oxygen through the hydrogen evolution reaction (HER) at the cathode and the oxygen evolution reaction (OER) at the anode, respectively. The electrolysis process can be expressed by eqn (1)–(3).

Question: What's the cathode?

Question: What's the anode?
Lithium-ion/sulfur (Li-ion/S) batteries consisting of metallic lithium-free anodes and sulfur cathodes are promising energy storage solutions. Anode prelithiation enables the Li-ion/S battery assembly with the extensively-developed sulfur cathodes. However, it’s very challenging owing to the low lithiation potentials of anode materials (e.g. Al, 0.32 V vs. Li/Li+). Here, a free-standing LiAl alloy anode (c-LiAl) is prepared via an easy-to-implement chemical prelithiation, by using a newly exploited reagent of lithium 9,9-dimethylfluorene (Li-DiMF) with a lower redox potential of 0.22 V vs. Li/Li+. Compared with the LiAl anode prepared by electrochemical prelithiation (e-LiAl) and the lithium metal anode by electrodeposition (e-Li/Cu), the c-LiAl displays a superior cyclability in half cell test and high resistance towards polysulfide or ambient-air corrosion. When paired with a sulfur cathode, the resulting Li-ion/S battery with c-LiAl demonstrates a much better cycling performance than the Li-ion/S battery with e-LiAl and the lithium/sulfur battery with e-Li/Cu.

Question: What's the cathode?
Answer: sulfur

Question: What's the anode?
Answer:  LiAl alloy

Question: What's the anode?
Answer: LiAl
The data for organic-based anode materials are provided in Table 2. Only a few reports, which were discussed in Section 3.3, were dedicated to aqueous batteries. For this reason, the summary and outlook will be focusing on the non-aqueous systems. As in the case of cathode materials (Section 2.7), we chose several inorganic benchmarks, which showed superior capacities, rate capabilities or cycling stability. These benchmarks include graphite, porous carbon (p. C), N-doped carbon (N-d. C), bismuth, antimony, iron disulfide and red phosphorous.

Question: What's the cathode?

Question: What's the anode?
Answer: organic-based
We explore a novel ether aided superconcentrated ionic liquid electrolyte; a combination of ionic liquid, N-propyl-N-methylpyrrolidinium bis(fluorosulfonyl)imide (C3mpyrFSI) and ether solvent, 1,2 dimethoxy ethane (DME) with 3.2 mol/kg LiFSI salt, which offers an alternative ion-transport mechanism and improves the overall fluidity of the electrolyte. The molecular dynamics (MD) study reveals that the coordination environment of lithium in the ether aided ionic liquid system offers a coexistence of both the ether DME and FSI anion simultaneously and the absence of ‘free’, uncoordinated DME solvent. These structures lead to very fast kinetics and improved current density for lithium deposition-dissolution processes. Hence the electrolyte is used in a lithium metal battery against a high mass loading (~12 mg/cm2) LFP cathode which was cycled at a relatively high current rate of 1mA/cm2 for 350 cycles without capacity fading and offered an overall coulombic efficiency of >99.8 %. Additionally, the rate performance demonstrated that this electrolyte is capable of passing current density as high as 7mA/cm2 without any electrolytic decomposition and offers a superior capacity retention. We have also demonstrated an ‘anode free’ LFP-Cu cell which was cycled over 50 cycles and achieved an average coulombic efficiency of 98.36%. The coordination chemistry and (electro)chemical understanding as well as the excellent cycling stability collectively leads toward a breakthrough in realizing the practical applicability of this ether aided ionic liquid electrolytes in lithium metal battery applications, while delivering high energy density in a prototype cell.

Question: What's the cathode?
Answer: LFP

Question: What's the anode?
2.1.5 Electrochemical performance measurements. The electrochemical performances of an individual electrode, Fe-intercalated ML Ti3C2Tx anode, and graphite cathode were examined in a three-electrode system in an Ar-filled glove box with O2 and H2O levels below 0.1 ppm, using platinum foil as the counter electrode and a silver-ion electrode as the reference electrode. For full device testing, a two-electrode electrolyzer was employed, with an Fe-intercalated ML Ti3C2Tx anode and graphite cathode. The electrolyte was 1 M EMIm+[PF6]− ionic liquid (1.2 mL) dissolved in PC (1.5 mL) and EMC (3 mL) solvent. CV and GCD experiments were performed using a CHI660E electrochemical workstation (Chenhua, China). EIS was conducted at open-circuit potential, with an amplitude of 5 mV and frequencies ranging from 10 mHz to 100 kHz.

Question: What's the cathode?
Answer: graphite

Question: What's the anode?
Answer: Fe-intercalated ML Ti3C2Tx

Question: What's the cathode?
Answer: graphite
The increased environmental hazards from the use of carbon-emitting fuels and the rapid depletion of conventional fossil fuels have triggered the research community to find alternatives to fossil-fuel-based technologies. In many innovative approaches to address these challenges, electrocatalytic water splitting driven by a renewable energy input to produce clean H2 has been widely viewed as a promising strategy as hydrogen is produced from renewable sources (such as solar and wind energy), which can be stored, transported and consumed without generating any carbon-based byproducts. Electrolysers are a crucial factor for water electrolysis. Currently, great efforts are being made to develop new electrocatalysts with high efficiency for overall water splitting. In addition to the advancement of electrocatalysts, another equally important aspect of water electrolysis is the development of novel electrolyzer design. The conventional cell design of a alkaline water electrolyser is illustrated in Scheme 1a. Both electrodes are dipped into an aqueous alkaline electrolyte with a separator (ion exchange membrane or porous diaphragm) between them. H2 and O2 are produced on the electrodes via two half-cell reactions: the hydrogen evolution reaction (HER), and the oxygen evolution reaction (OER). In the lab, these electrolysers are used directly, while in industry, these electrolysers are used in stacks to scale-up H2 production. For electrolysers, major costs are due to the fabrication and material for the three main components: anodes, cathodes and separators. The existence of a separator not only increases the cost of the electrolyser, but also induces extra overpotentials for water splitting. A new electrolyser with a simple, condensed, membrane-free design is highly desired since it not only requires lower overpotentials, but also needs smaller areas and fewer materials, which reduces the overall cost of the electrolyser cells and promotes the electrochemical water splitting.

Question: What's the cathode?

Question: What's the anode?
For full cell testing, sulfur–carbon composite cathodes were used. It is well known that S, lithium disulfide and other reaction intermediates have poor electronic conductivity. To improve this, S nanoparticles were impregnated into a nitrogen doped carbon matrix (from now on labelled ‘S/NC’); a detailed account on the synthesis of the cathode was given in our previous report. The carbon composite matrix with good electronic conductivity and a high surface area (700 m2 g−1) contained graphene and multiwall carbon nanotubes in an equal weight ratio. The morphology of the cathode material is illustrated in the SEM image shown in Fig. S4.† Further, thermo-gravimetric analysis (TGA) shows a S loading of ∼55 wt% in the S/NC cathode (Fig. S5, ESI†).

Question: What's the cathode?
Answer: sulfur–carbon composite

Question: What's the cathode?
Answer:  S/NC
The data for organic-based cathode materials are summarized in Table 1. All these compounds were reported for non-aqueous batteries, which should be mainly due to the mismatch between their working potentials and water stability voltage window. Some n-type materials, such as quinones or aromatic imides, can operate without decomposition of water, especially with highly concentrated electrolytes. However, their working potentials are close to the onset of the hydrogen evolution reaction, which makes them more suitable for anodes rather than for cathodes (see Section 3.3). There are several reports on aromatic amines and nitroxyl radicals as cathodes for aqueous Li-, Na-, Zn- and ammonium-based cells. It might be expected that similar K-based aqueous dual-ion batteries will become successful in the future.

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

Question: What's the anode?
The working electrode was composed of carbon paper, the as-prepared electrocatalysts (70 wt%), super P (20 wt%) and a PVDF binder (10 wt%). The mass loading of the electrocatalysts on the carbon paper was 0.6–0.8 mg cm−2. The electrolyte was 1 M lithium bis (trifluoromethane) sulfonimide, LiTFSI, in dimethyl sulfoxide (DMSO). 2032-type coin LOBs, which included a lithium metal anode (Ø = 15 mm), a glass-fiber separator (GFC, Whatman, Ø = 19 mm) impregnated with an electrolyte, and a well-prepared cathode (Ø = 14 mm), were assembled in a glove box filled with high purity Ar. The electrochemical performance of the assembled LOBs was measured in a sealed home-made container filled with high purity O2. The galvanostatic discharge–charge tests were carried out on a LAND BT 2000 battery testing system. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were conducted on a CHI 604B electrochemical workstation. Before each electrochemical test, the as-assembled LOBs were first equilibrated for several hours. In this work, all the current densities and specific capacities of LOBs were normalized by the actual mass loading of the active materials.

Question: What's the cathode?

Question: What's the anode?
Answer: lithium metal
In this review, we have provided a comprehensive overview of the design, synthesis, and application of metal sulfides in rechargeable Li–S batteries. We aimed to summarize important concepts to boost the practical development of high-energy-density Li–S batteries. As a promising polar substrate, metal sulfides have considerable benefits, including a moderately strong affinity for active sulfide binding, high electronic conductivity, the ability to modulate redox reaction kinetics, and a high activity capacity contribution. Through the use of metal sulfides, great progress has been made in improving sulfur cathodes, design of interlayers, modification of separators, and protection of lithium anodes. Despite these achievements, challenges remain in terms of developing affordable large-scale synthesis techniques, elucidating an in-depth mechanism of binding LiPSs, enhancing the rationality and reliability of theoretical simulations, and building stable high-energy-density Li–S batteries over routine LIBs. We hope that this review will inspire greater interest in the use of metal sulfides and other related materials with similar effects as polar substrates for the exploitation of advanced Li–S batteries.

Question: What's the cathode?
Answer: sulfur

Question: What's the anode?
Answer: lithium
As a supplementary experiment to further confirm this advantageous effect of the DETA CB powders, we fabricated a coin-type (2032R) half cell (printed LCO cathode/liquid electrolyte (1 M LiPF6 in EC/PC (1/1 (v/v)))-filled polyethylene separator/Li metal anode) and investigated its electrochemical performance. The cell containing the DETA CB powders showed the higher discharge rate capability compared to its counterpart containing the pristine CB powders at a fixed charge current density of 0.1C (Fig. S4B†). Moreover, the cell with the DETA CB powders exhibited the higher charge rate capability at a fixed discharge current density of 0.1C (Fig. S4C†). It should be noted that this superior charge rate capability enabled by the DETA CB powders is expected to improve the storage efficiency of the electric energy generated by the cSiPV module.

Question: What's the cathode?
Answer: LCO

Question: What's the electrolyte?
Answer: 1 M LiPF6 in EC/PC (1/1 (v/v))
In voltage research, the advantages of cathode exfoliation and anode exfoliation can be combined by using the voltage of the changing direction, and the process of electrolyte intercalation and gas expansion can be brought into full play.

Question: What's the cathode?

Question: What's the anode?
In order to get rid of templates, many efforts have been attempted. CP nanowire electrochemically polymerized and assembled onto two biased electrodes (anode and cathode) immersed in aqueous monomer solutions. The essence of this method is an electrode-wire-electrode or electrode-wire-target assembly. For instance, CP nanowires are prepared by an electro-deposition within channels between two electrodes on the surface of silicon wafers. By using this way, Chouvy et al. prepared oriented PPy nanowires and found the diameter and the length of the nanowires can be increased when the solution contained a high concentration of weak-acid anions and a low concentration of non-acidic anions. Since electrochemical polymerization is a shared and controlled method for preparing CPs and their nanostructures, electro-deposition within channels between two electrodes has received attention in fabricating molecule devices.

Question: What's the cathode?

Question: What's the anode?
Spherical [Ni0.5Mn0.5](OH)2 precursors were synthesized by the co-precipitation method. Stoichiometric amounts of NiSO4·6H2O and MnSO4·H2O (Samchun Chemical, Korea) were used as starting materials for [Ni0.5Mn0.5](OH)2. The metal solution concentration (2 mol L−1 for the metal solution), pH (∼11.0), temperature (45 °C), and stirring speed of the mixture in the batch-type reactor were carefully controlled. At the same time, aqueous NaOH (Samchun, Korea; NaOH/transition metal molar ratio = 2:1) and aqueous NH4OH (Junsei, Japan; NH4OH/transition metal molar ratio = 1.1:1) as chelating agents were separately fed into the reactor. The precursor powders were obtained by filtering, washing and vacuum drying at 110 °C overnight. For the Na[Ni0.5Mn0.5]O2 cathode, the obtained spherical precursors were mixed with Na2CO3 (Na:[Ni + Mn] molar ratio = 1.05:1, 5% excess Na2CO3), calcined at 800 °C for 24 h in an oxygen atmosphere, and quenched under vacuum conditions. For Ca-substituted Na1−2xCax[Ni0.5Mn0.5]O2 cathodes, an appropriate amount of Ca(OH)2 was mixed with the [Ni0.5Mn0.5](OH)2 precursor and Na2CO3 (Na:Ca:[Ni + Mn] molar ratio = 1.05–2x:x:1, x = 0.01, 0.02, and 0.03) in the same calcination process.

Question: What's the cathode?
Answer: Na[Ni0.5Mn0.5]O

Question: What's the cathode?
Answer: Na1−2xCax[Ni0.5Mn0.5]O2
Besides lithium, a modern LIB typically contains non-widespread transition metals, such as copper (anode current collector), nickel and cobalt (cathode materials). The shortage in cobalt is especially acute. If cobalt-free batteries remain underdeveloped, the production of Co will have to increase up to an order of magnitude to satisfy the future demand. Additionally, extraction and processing of transition metals might be harmful to the environment and is typically energy-intensive.

Question: What's the cathode?
Answer: nickel and cobalt

Question: What's the anode?
Answer: copper
Later, Chen et al. used K2TP under similar conditions as the anode for hybrid supercapacitors. Activated carbon was used as the cathode. Energy of 101 W h kg−1 and power of 2.16 kW kg−1 based on the mass of two electrodes were demonstrated. If the electrolyte mass was included, the values reached 41.5 W h kg−1 and 885 W kg−1, respectively. The capacity retention of the supercapacitor was 97.7% in 500 cycles. In half cells, the capacity of K2TP at 5 A g−1 was 124 mA h g−1.

Question: What's the cathode?
Answer: carbon

Question: What's the anode?
Answer: K2TP
To obtain strong immobilization and fast conversion kinetics for polysulfides, the concept of constructing highly adsorptive and catalyzing heterostructures has been widely developed, such as TiN–TiO2, MoN–VN, and WS2–WO3. In fact, the anchoring of polysulfides as well as Li2S precipitation are part of a continuous multielectron redox reaction in a working battery, and thus an integrated platform, such as 1T MoS2 NDs in this work, enabling smooth “immobilization–diffusion–conversion” is highly appealing. The unique advantages for 1T MoS2 ND can be summarized as following: (i) the edge-rich NDs with an intrinsically strong affinity to polysulfides serve as anchoring sites for LPSs and accelerate their reduction, which contributes to the long cycle life and high sulfur utilization; (ii) the highly conductive and catalytic nature of 1T MoS2 NDs uniformly loaded on conductive substrates can facilitate Li–S reaction kinetics (Fig. S14, ESI†) and reduce the cell resistance, which benefits the high rate performance of MoS2 ND-modified cathodes; (iii) the well-defined morphology and phase of MoS2 maximize the active sites to fully demonstrate their potential for Li–S chemistry, which enables a boost of the electrochemical performance with a small amount of electrochemical inert catalysts. In addition, post-mortem analyses revealed that MoS2 NDs/porous carbon remained stable after cycling (Fig. S15, ESI†). To further determine whether the excellent catalytic performance of the MoS2 NDs could be retained during long-term cycling, the MoS2 ND/porous carbon/Li2S6 cathode was prolonged to 500 cycles at 0.5C (Fig. S16, ESI†), and exhibited only a low capacity fading rate of 0.08% per cycle, directly indicating the stability of the MoS2 NDs as a catalyst in long-term Li–S batteries. Finally, thanks to the facile fabrication method and the low content needed to improve LSB performance, the large-scale application of 1T MoS2 NDs in high-energy LSBs should not be problematic.

Question: What's the cathode?
Answer: MoS2 ND-modified

Question: What's the cathode?
Answer: MoS2 ND/porous carbon/Li2S6
For full cells, commercial lithium iron phosphate (LFP) was used as the cathode material. A mixture of LFP powder, acetylene black (conductive additive) and polyvinylidene fluoride (PVDF) with a mass ratio of 8:1:1 in N-methyl-2-pyrrolidone (NMP) was first coated on aluminum foil, dried in a vacuum oven at 80 °C overnight and used as the LFP cathode. The areal mass loading of LFP was around 5 mg cm−2. The charge–discharge voltage was recorded from 2.0 to 4.0 V while the current rate varied from 0.2 to 2.0C (1C is equals to 170.0 mA h g−1). Electrochemical impedance spectroscopy (EIS) measurements were performed on an IVIUM electrochemical workstation with a frequency range of 105–0.01 Hz.

Question: What's the cathode?
Answer:  lithium iron phosphate (LFP)

Question: What's the cathode?
Answer: LFP
The determination of metal and polymer material moduli are straightforward and taken from literature values. To verify the estimated moduli of the composite electrodes, they were stacked in various layers and acoustically interrogated. As shown in Fig. 3a, the graphite/Cu electrode has a modulus of 10.7 GPa, and the LiCoO2/Al electrode has a modulus of around 27.8 GPa, as calculated from the measured wave velocities (Fig. 3c) and the respective weighted densities of the double-sided electrodes. These values are slightly higher than the respective Hashin–Shtrikman bounds because the measured electrodes include the metal current collector which has a higher modulus. The values are lower than the single particle graphite or LiCoO2 because the composite electrodes are weighted down by the softer materials. The change in thickness of these individual electrodes during cycling can also be estimated from average peak-to-peak spacing of the intensity line profiles generated from TXM micrographs (Fig. S3†). These peak-to-peak intensities vary because of pouch cell manufacturing tolerances: the electrodes are not perfectly aligned within the cell, causing signal blurring at electrode boundaries. This percent error in thickness calculation is minimized by introducing threshold values for peak discrimination. The results of the peak spacing analysis (Fig. S4†) show that the average single layer expands upon charge and contracts upon discharge, and that the degree of hysteresis grows with current rate. The initial average electrode thickness of 170 μm confirms the ex situ digital caliper measurements of individual electrodes (180 μm for LiCoO2/Al and 200 μm for graphite/Cu) and the moduli estimation of 27.8 GPa for LiCoO2/Al and 10.7 GPa for graphite/Cu. Unfortunately, the differences in thickness changes between LiCoO2/Al and graphite/Cu during cycling are hard to discern due to the imperfect alignment of the electrode layers with the X-ray detector. For future studies, improved spatial resolution at the single electrode length scale would be aided by tests of single-layer pouch cells, where thicknesses of the single anode and cathode could be measured more accurately without stack distortion.

Question: What's the cathode?

Question: What's the anode?
Volumetric capacity and density are usually unreported for organic materials used in potassium batteries. Density for solid polar organic compounds containing only C, H, N and O ranges between roughly 1.1 and 1.7 g cm−3, and it is smaller than for inorganic cathode materials (calc. 2.3 g cm−3 for KMHCF, calc. 3.1 g cm−3 for KVPO4F, and 3.35 g cm−3 for V2O5 ( )). This limits the applicability of organic cathode materials where the low device volume is crucial, e.g., in portable electronics. However, in some electric vehicles and large-scale stationary applications the volume is supposed to be less restricted.

Question: What's the cathode?
Answer: KMHCF

Question: What's the cathode?
Answer: KVPO4F
Against this backdrop, the presently reported work focuses on designing a composition (viz., combination of TM- and non-TM-ions) and suitably tuning some structural features of O3-type Na-TM-oxide based cathode materials to address the main issue concerning stability against hydration and also improve the electrochemical cyclic stability, as well as rate capability. While doing so, a strong correlation between the composition, structure, stability against hydration and electrochemical behavior/performance for such oxides has been established. As will be demonstrated, an air/water-stable (despite long-term exposures under stringent conditions) O3-type Na-TM-oxide has been developed, which is devoid of all the problems mentioned above, so much so that it allows the successful development of stable electrodes using a cost-effective and environment/health friendly ‘water based binder’ (i.e., Na-alginate) and water as solvent during electrode preparation (viz., ‘aqueous processing’). To the best of our knowledge, such excellent stability against hydration and electrochemical performance, despite being ‘aqueous-processed’, have not been reported earlier for O3-type Na-TM-oxide based cathodes.

Question: What's the cathode?
Answer: O3-type Na-TM-oxide based

Question: What's the cathode?
Answer: O3-type Na-TM-oxide based