milerssliu/battery-device-data-qa huggingface dataset:
Despite the merits of zinc anode, ARZIBs are still at a development stage due to the lack of suitable Zn-ion host materials. To date, various materials have been explored as cathodes for ARZIBs, such as manganese-based oxides, Prussian blue analogues, polyanionic compounds, and vanadium-based compounds. However, most of the reported cathode materials suffer from insufficient rate capability, low capacity, and energy density. The main reasons can be ascribed to three factors: (i) the relativity poor conductivity leads to sluggish ion/electron transport kinetics, especially in quasi-solid-state electrolytes; (ii) the use of non-active additives such as polyvinylidene fluoride and polypyrrole, which were usually employed to ameliorate the flexibility of powder-formed active materials, would inevitably increase the “dead mass” of the cathode, thus limiting the overall energy density of the full devices; (iii) the increased contact resistance between the active materials and the current collector, and the interfacial resistance between the electrode and electrolyte, arising from the repeated reversible Zn2+ (de)intercalation processes, further result in a decrease in the high rate ability. Therefore, there is an urgent demand to explore free-standing materials that can adequately accommodate Zn2+ insertion/extraction rapidly and steadily to promote the progress of ARZIBs.

Question: What's the electrolyte?
The electrochemical performance of the PAM/PVP-coated Zn–AC hybrid ion supercapacitors was tested by cyclic voltammetry and galvanostatic charge–discharge tests within the voltage range of 0–2.0 V (Fig. 5). The CV curves of the hybrid ion capacitors at various scan rates from 10 mV s−1 to 200 mV s−1 maintain a quasi-rectangular shape, suggesting an EDLC-type behavior (Fig. 5a). Fig. 5b shows the voltage curves of the PAM/PVP-coated Zn–AC hybrid ion supercapacitors at various current densities from 0.5–30 A g−1. The symmetric and linear shape of the curves in the graph can be observed corresponding to the results of the CV test. At a current density of 1 A g−1, the bare Zn–AC hybrid ion supercapacitors failed after 10 cycles, while the PAM/PVP-coated Zn–AC hybrid ion supercapacitors show a good cycling stability (Fig. S10†). This superior stability can be attributed to the critical role of the PAM/PVP layer coated on the zinc anode acting as an inhibitor on the O2/water interphase and a distributor of ions during the zinc deposition. The PAM/PVP-coated Zn–AC hybrid ion supercapacitors show an excellent rate capability of 336, 292, 264, 232, 220, 195, 190, 175, and 165 F g−1 at a current density of 0.5, 1, 2, 5, 8, 10, 15, 20, 25, and 30 A g−1 (Fig. 5c and S11†). The galvanostatic charge–discharge curves and long cycling stability of the PAM/PVP-coated Zn–AC hybrid ion supercapacitors at a current density of 15 A g−1 are shown in Fig. 5d and e. The specific capacitance of the devices slightly increases at first due to activation, then remains quite stable, and ultimately gives a high retention of 100% of the initial specific capacitance after 6000 cycles. These results further demonstrate the excellent electrochemical performance of the Zn–AC hybrid ion supercapacitors with the PAM/PVP layer. Notably, the PAM/PVP-coated Zn–AC hybrid ion supercapacitors have a high energy density of 118 W h−1 kg−1 and a power density of 17.9 kW kg−1 (based on the mass of AC materials, Fig. S12†), where the energy density is superior to those of the bare Zn–AC hybrid ion supercapacitors (Fig. S13 and Table S1†).

Question: What's the anode?
Answer: zinc
The electrochemical performance of the PAM/PVP-coated Zn–AC hybrid ion supercapacitors was tested by cyclic voltammetry and galvanostatic charge–discharge tests within the voltage range of 0–2.0 V (Fig. 5). The CV curves of the hybrid ion capacitors at various scan rates from 10 mV s−1 to 200 mV s−1 maintain a quasi-rectangular shape, suggesting an EDLC-type behavior (Fig. 5a). Fig. 5b shows the voltage curves of the PAM/PVP-coated Zn–AC hybrid ion supercapacitors at various current densities from 0.5–30 A g−1. The symmetric and linear shape of the curves in the graph can be observed corresponding to the results of the CV test. At a current density of 1 A g−1, the bare Zn–AC hybrid ion supercapacitors failed after 10 cycles, while the PAM/PVP-coated Zn–AC hybrid ion supercapacitors show a good cycling stability (Fig. S10†). This superior stability can be attributed to the critical role of the PAM/PVP layer coated on the zinc anode acting as an inhibitor on the O2/water interphase and a distributor of ions during the zinc deposition. The PAM/PVP-coated Zn–AC hybrid ion supercapacitors show an excellent rate capability of 336, 292, 264, 232, 220, 195, 190, 175, and 165 F g−1 at a current density of 0.5, 1, 2, 5, 8, 10, 15, 20, 25, and 30 A g−1 (Fig. 5c and S11†). The galvanostatic charge–discharge curves and long cycling stability of the PAM/PVP-coated Zn–AC hybrid ion supercapacitors at a current density of 15 A g−1 are shown in Fig. 5d and e. The specific capacitance of the devices slightly increases at first due to activation, then remains quite stable, and ultimately gives a high retention of 100% of the initial specific capacitance after 6000 cycles. These results further demonstrate the excellent electrochemical performance of the Zn–AC hybrid ion supercapacitors with the PAM/PVP layer. Notably, the PAM/PVP-coated Zn–AC hybrid ion supercapacitors have a high energy density of 118 W h−1 kg−1 and a power density of 17.9 kW kg−1 (based on the mass of AC materials, Fig. S12†), where the energy density is superior to those of the bare Zn–AC hybrid ion supercapacitors (Fig. S13 and Table S1†).

Question: What's the electrolyte?
The intermediate LiPSs generated from charge/discharge processes can spontaneously dissolve into the electrolyte and freely migrate between the cathode and the anode through the separator, resulting in the loss of active materials, passivation of both the electrodes, and unavoidable self-discharge/recharge. So far two typical strategies covering physical confinement and chemical adsorption have been proven and generally accepted as an effective solution to address this issue. Physical confinement often relies on the high surface area or pore structure of the host materials, while chemical adsorption depends on the strong interaction between the host materials and LiPS species. Accordingly, rationally creating metal sulfides with a desired surface area, well-designed porosity, enhanced surface polar/selectivity, and tailored crystalline form has been achieved by a variety of approaches, e.g. solvothermal/hydrothermal methods, ball-milling technology, coprecipitation method, and innovative heat treatment technology.

Question: What's the cathode?
The intermediate LiPSs generated from charge/discharge processes can spontaneously dissolve into the electrolyte and freely migrate between the cathode and the anode through the separator, resulting in the loss of active materials, passivation of both the electrodes, and unavoidable self-discharge/recharge. So far two typical strategies covering physical confinement and chemical adsorption have been proven and generally accepted as an effective solution to address this issue. Physical confinement often relies on the high surface area or pore structure of the host materials, while chemical adsorption depends on the strong interaction between the host materials and LiPS species. Accordingly, rationally creating metal sulfides with a desired surface area, well-designed porosity, enhanced surface polar/selectivity, and tailored crystalline form has been achieved by a variety of approaches, e.g. solvothermal/hydrothermal methods, ball-milling technology, coprecipitation method, and innovative heat treatment technology.

Question: What's the anode?
The intermediate LiPSs generated from charge/discharge processes can spontaneously dissolve into the electrolyte and freely migrate between the cathode and the anode through the separator, resulting in the loss of active materials, passivation of both the electrodes, and unavoidable self-discharge/recharge. So far two typical strategies covering physical confinement and chemical adsorption have been proven and generally accepted as an effective solution to address this issue. Physical confinement often relies on the high surface area or pore structure of the host materials, while chemical adsorption depends on the strong interaction between the host materials and LiPS species. Accordingly, rationally creating metal sulfides with a desired surface area, well-designed porosity, enhanced surface polar/selectivity, and tailored crystalline form has been achieved by a variety of approaches, e.g. solvothermal/hydrothermal methods, ball-milling technology, coprecipitation method, and innovative heat treatment technology.

Question: What's the electrolyte?
Bulk heterojunction (BHJ) polymer solar cells (PSCs) that convert absorbed sunlight into electrical energy have been in the spotlight due to their potential in large-scale and cost-effective roll-to-roll fabrication. In the past decade, massive endeavors concerning the development and interfacial engineering of novel light-harvesting materials have been made to improve the power conversion efficiency (PCE). Nowadays, the highest PCE exceeds 16% for single-junction BHJ PSCs. Interface layers, positioned between the photoactive layer and the anode/cathode electrode, play vital roles in governing the performance of PSCs. Interface layers are usually utilized to tailor the work function of the electrode for charge carrier collection maximization, modify the interface to alter the photoactive layer micromorphology, as well as minimize carrier recombination at the interfaces between the active layer and the transport layer. For a hole transport layer (HTL), pivotal parameters consist of high conductivity, high transparency, solution processability, favorable stability, etc. PEDOT:PSS, as the state-of-the-art hole transport material in organic optoelectronic devices, possesses outstanding edges of high transmittance in the visible spectrum and superior film-forming ability and thermal stability. However, PEDOT:PSS solution is strongly acidic and hygroscopic, which can etch the indium tin oxide (ITO) anode. Moreover, it has been verified that the spin-casted PEDOT:PSS thin film often exhibits inhomogeneous morphology and poor electrical conductivity, leading to poor efficiency and stability of devices. The development of a PEDOT:PSS HTL that possesses interconnected conductive domains and enhanced electrical conductivity is crucial to PSCs.

Question: What's the cathode?
Bulk heterojunction (BHJ) polymer solar cells (PSCs) that convert absorbed sunlight into electrical energy have been in the spotlight due to their potential in large-scale and cost-effective roll-to-roll fabrication. In the past decade, massive endeavors concerning the development and interfacial engineering of novel light-harvesting materials have been made to improve the power conversion efficiency (PCE). Nowadays, the highest PCE exceeds 16% for single-junction BHJ PSCs. Interface layers, positioned between the photoactive layer and the anode/cathode electrode, play vital roles in governing the performance of PSCs. Interface layers are usually utilized to tailor the work function of the electrode for charge carrier collection maximization, modify the interface to alter the photoactive layer micromorphology, as well as minimize carrier recombination at the interfaces between the active layer and the transport layer. For a hole transport layer (HTL), pivotal parameters consist of high conductivity, high transparency, solution processability, favorable stability, etc. PEDOT:PSS, as the state-of-the-art hole transport material in organic optoelectronic devices, possesses outstanding edges of high transmittance in the visible spectrum and superior film-forming ability and thermal stability. However, PEDOT:PSS solution is strongly acidic and hygroscopic, which can etch the indium tin oxide (ITO) anode. Moreover, it has been verified that the spin-casted PEDOT:PSS thin film often exhibits inhomogeneous morphology and poor electrical conductivity, leading to poor efficiency and stability of devices. The development of a PEDOT:PSS HTL that possesses interconnected conductive domains and enhanced electrical conductivity is crucial to PSCs.

Question: What's the anode?
Answer: indium tin oxide (ITO)
Bulk heterojunction (BHJ) polymer solar cells (PSCs) that convert absorbed sunlight into electrical energy have been in the spotlight due to their potential in large-scale and cost-effective roll-to-roll fabrication. In the past decade, massive endeavors concerning the development and interfacial engineering of novel light-harvesting materials have been made to improve the power conversion efficiency (PCE). Nowadays, the highest PCE exceeds 16% for single-junction BHJ PSCs. Interface layers, positioned between the photoactive layer and the anode/cathode electrode, play vital roles in governing the performance of PSCs. Interface layers are usually utilized to tailor the work function of the electrode for charge carrier collection maximization, modify the interface to alter the photoactive layer micromorphology, as well as minimize carrier recombination at the interfaces between the active layer and the transport layer. For a hole transport layer (HTL), pivotal parameters consist of high conductivity, high transparency, solution processability, favorable stability, etc. PEDOT:PSS, as the state-of-the-art hole transport material in organic optoelectronic devices, possesses outstanding edges of high transmittance in the visible spectrum and superior film-forming ability and thermal stability. However, PEDOT:PSS solution is strongly acidic and hygroscopic, which can etch the indium tin oxide (ITO) anode. Moreover, it has been verified that the spin-casted PEDOT:PSS thin film often exhibits inhomogeneous morphology and poor electrical conductivity, leading to poor efficiency and stability of devices. The development of a PEDOT:PSS HTL that possesses interconnected conductive domains and enhanced electrical conductivity is crucial to PSCs.

Question: What's the electrolyte?
LiMn2O4 (LMO) was used as a cathode to evaluate the electrochemical performance of Al2O3-coated LTO in the WiSE (Fig. S5†). The mass ratio of LMO:LTO was set as 2.5:1 to accommodate the low CE of LTO during the initial several cycles. 1C was used instead of a high rate to demonstrate the stability of the electrolyte in the full cell. Such LTO/LMO full cells delivered a voltage plateau at ∼2.4 V during discharge. The discharging capacity based on LTO mass was 145 mA h g−1. In the first cycle, a coulombic efficiency (CE) of 84.5% was delivered, indicating that a relatively small amount of electrolyte was consumed to form an additional LiF-rich SEI on the Al2O3-coated LTO anode. In comparison, pairing the uncoated LTO and LMO delivered a CE of 50% (Fig. S6†), further confirming the effect of the Al2O3 coating in suppressing the side reaction. As we reported previously, the reduction of salt anions bis(trifluoromethane sulfonyl)imide (TFSI) occurs between 1.9 V and 2.9 V. Although reduction of TFSI anions is expected to occur if an Al2O3 coating is absent (Fig. S7†), formation of a complete SEI needs a long time (i.e., few cycles in galvanostatic charge/discharge cycles). The lithiation potential of pristine LTO resides beyond the cathodic limit of the WiSE, so a significant HER will occur before lithiation. The persistent evolution of gas undoubtedly prevents complete formation of the SEI. For the initial cycles, when a robust SEI has not been constructed, protection of the Al2O3 surface serves as a key barrier to ensure that SEI chemistry occurs, and that the SEI ingredient formed from the reduction of the TFSI anion adheres to the anode surface. After the most challenging period in the initial cycles, a dense and complete SEI will come into shape (Fig. S7†), eventually providing long-term protection and allowing LTO to deliver a reversible capacity.

Question: What's the cathode?
Answer: LiMn2O4 (LMO)
LiMn2O4 (LMO) was used as a cathode to evaluate the electrochemical performance of Al2O3-coated LTO in the WiSE (Fig. S5†). The mass ratio of LMO:LTO was set as 2.5:1 to accommodate the low CE of LTO during the initial several cycles. 1C was used instead of a high rate to demonstrate the stability of the electrolyte in the full cell. Such LTO/LMO full cells delivered a voltage plateau at ∼2.4 V during discharge. The discharging capacity based on LTO mass was 145 mA h g−1. In the first cycle, a coulombic efficiency (CE) of 84.5% was delivered, indicating that a relatively small amount of electrolyte was consumed to form an additional LiF-rich SEI on the Al2O3-coated LTO anode. In comparison, pairing the uncoated LTO and LMO delivered a CE of 50% (Fig. S6†), further confirming the effect of the Al2O3 coating in suppressing the side reaction. As we reported previously, the reduction of salt anions bis(trifluoromethane sulfonyl)imide (TFSI) occurs between 1.9 V and 2.9 V. Although reduction of TFSI anions is expected to occur if an Al2O3 coating is absent (Fig. S7†), formation of a complete SEI needs a long time (i.e., few cycles in galvanostatic charge/discharge cycles). The lithiation potential of pristine LTO resides beyond the cathodic limit of the WiSE, so a significant HER will occur before lithiation. The persistent evolution of gas undoubtedly prevents complete formation of the SEI. For the initial cycles, when a robust SEI has not been constructed, protection of the Al2O3 surface serves as a key barrier to ensure that SEI chemistry occurs, and that the SEI ingredient formed from the reduction of the TFSI anion adheres to the anode surface. After the most challenging period in the initial cycles, a dense and complete SEI will come into shape (Fig. S7†), eventually providing long-term protection and allowing LTO to deliver a reversible capacity.

Question: What's the anode?
Answer: Al2O3-coated LTO
LiMn2O4 (LMO) was used as a cathode to evaluate the electrochemical performance of Al2O3-coated LTO in the WiSE (Fig. S5†). The mass ratio of LMO:LTO was set as 2.5:1 to accommodate the low CE of LTO during the initial several cycles. 1C was used instead of a high rate to demonstrate the stability of the electrolyte in the full cell. Such LTO/LMO full cells delivered a voltage plateau at ∼2.4 V during discharge. The discharging capacity based on LTO mass was 145 mA h g−1. In the first cycle, a coulombic efficiency (CE) of 84.5% was delivered, indicating that a relatively small amount of electrolyte was consumed to form an additional LiF-rich SEI on the Al2O3-coated LTO anode. In comparison, pairing the uncoated LTO and LMO delivered a CE of 50% (Fig. S6†), further confirming the effect of the Al2O3 coating in suppressing the side reaction. As we reported previously, the reduction of salt anions bis(trifluoromethane sulfonyl)imide (TFSI) occurs between 1.9 V and 2.9 V. Although reduction of TFSI anions is expected to occur if an Al2O3 coating is absent (Fig. S7†), formation of a complete SEI needs a long time (i.e., few cycles in galvanostatic charge/discharge cycles). The lithiation potential of pristine LTO resides beyond the cathodic limit of the WiSE, so a significant HER will occur before lithiation. The persistent evolution of gas undoubtedly prevents complete formation of the SEI. For the initial cycles, when a robust SEI has not been constructed, protection of the Al2O3 surface serves as a key barrier to ensure that SEI chemistry occurs, and that the SEI ingredient formed from the reduction of the TFSI anion adheres to the anode surface. After the most challenging period in the initial cycles, a dense and complete SEI will come into shape (Fig. S7†), eventually providing long-term protection and allowing LTO to deliver a reversible capacity.

Question: What's the electrolyte?
3Mg/Mg2Sn electrodes were subjected to galvanostatic C/D at various rates in Mg(HMDS)2/MgCl2. In addition to the unprecedented high capacity, the rate performance of 3Mg/Mg2Sn was also impressive. The stepwise increase in C/D rates resulted in a continuous decrease in reversible capacities, but the degree of reduction was not abrupt (Fig. 5A). For example, a reversible capacity of 805 mA h g−1 was delivered at 100 mA g−1 and as much as 87 and 53% (700 and 430 mA h g−1) of it was retained at 500 and 1500 mA g−1, respectively. Accordingly, the corresponding C/D profiles also showed a relatively small increase in overpotentials with an increase in the C/D rates (Fig. 5B). When compared with the plateau voltage at 100 mA g−1, the additional overpotential required at 1500 mA g−1 was only ca. ±50 mV. It should be stressed here that such excellence has never been reported for either alloy- or intercalation-type electrodes in MIBs. Most anode materials show a capacity of less than 400 mA h g−1 at a C/D rate lower than 100 mA g−1, which significantly decreases with increasing C/D rates (Table 1). A few materials can deliver reasonable capacities at high rates, but no performance has been comparable to that of 3Mg/Mg2Sn.

Question: What's the anode?
3Mg/Mg2Sn electrodes were subjected to galvanostatic C/D at various rates in Mg(HMDS)2/MgCl2. In addition to the unprecedented high capacity, the rate performance of 3Mg/Mg2Sn was also impressive. The stepwise increase in C/D rates resulted in a continuous decrease in reversible capacities, but the degree of reduction was not abrupt (Fig. 5A). For example, a reversible capacity of 805 mA h g−1 was delivered at 100 mA g−1 and as much as 87 and 53% (700 and 430 mA h g−1) of it was retained at 500 and 1500 mA g−1, respectively. Accordingly, the corresponding C/D profiles also showed a relatively small increase in overpotentials with an increase in the C/D rates (Fig. 5B). When compared with the plateau voltage at 100 mA g−1, the additional overpotential required at 1500 mA g−1 was only ca. ±50 mV. It should be stressed here that such excellence has never been reported for either alloy- or intercalation-type electrodes in MIBs. Most anode materials show a capacity of less than 400 mA h g−1 at a C/D rate lower than 100 mA g−1, which significantly decreases with increasing C/D rates (Table 1). A few materials can deliver reasonable capacities at high rates, but no performance has been comparable to that of 3Mg/Mg2Sn.

Question: What's the electrolyte?