milerssliu/battery-device-data-qa huggingface dataset:
Low-cost and high-safety aqueous Zn ion batteries have been considered as promising alternatives to Li-ion batteries, provided that a stable Zn metal anode could be developed. The dendrite growth and the low Coulombic efficiency (CE) are the primary two issues afflicting the design of advanced Zn metal anode. Inspired by the complexing agent in the electroplating industry, acetonitrile (AN) is proposed as an electrolyte additive to guide the smooth growth of Zn. The enhanced intermolecular interactions between Zn2+ and the mixed H2O/AN solvents lead to the supersaturating of adatoms on the current collector, as revealed by the complementary theoretical and experimental studies. Consequently, homogeneous nucleation and smooth growth of Zn is enabled for achieving exceptional stability up to 1000 cycles with an excellent CE of 99.64% on average. Application-wise, the incorporation of complexing agent in the electrolyte is fully compatible with the cathode while maintains the non-flammable nature for safe operation. The solvation chemistry regulation strategy provides a promising route to stabilize Zn metal anodes.

Question: What's the anode?
Answer: Zn metal
Low-cost and high-safety aqueous Zn ion batteries have been considered as promising alternatives to Li-ion batteries, provided that a stable Zn metal anode could be developed. The dendrite growth and the low Coulombic efficiency (CE) are the primary two issues afflicting the design of advanced Zn metal anode. Inspired by the complexing agent in the electroplating industry, acetonitrile (AN) is proposed as an electrolyte additive to guide the smooth growth of Zn. The enhanced intermolecular interactions between Zn2+ and the mixed H2O/AN solvents lead to the supersaturating of adatoms on the current collector, as revealed by the complementary theoretical and experimental studies. Consequently, homogeneous nucleation and smooth growth of Zn is enabled for achieving exceptional stability up to 1000 cycles with an excellent CE of 99.64% on average. Application-wise, the incorporation of complexing agent in the electrolyte is fully compatible with the cathode while maintains the non-flammable nature for safe operation. The solvation chemistry regulation strategy provides a promising route to stabilize Zn metal anodes.

Question: What's the electrolyte?
Novel portable power sources featuring high flexibility, built-in sustainability and enhanced safety have attracted ever-increasing attention in the field of wearable electronics. Herein, a novel flexible self-charging sodium-ion full battery was feasibly fabricated by sandwiching a BaTiO3-P(VDF-HFP)-NaClO4 piezoelectric gel-electrolyte film between an advanced Na3V2(PO4)3@C cathode and hard carbon anode. Besides the considerable flexibility and electrochemical storage performance, the as-designed device also delivers sound self-charging capability via various stress patterns, regardless of whether under static compression, repeated bending or continuous palm patting. Serially connected self-charging devices are able to drive several electronic devices with a good working state. Specifically, a unique theory of electromagnetic fields was successfully introduced to deduce the direct self-charging mechanism, where no rectifier was applied and the battery was charged by the built-in piezoelectric component. This work presents an innovative approach to achieve a new sustainable, safe and flexible sodium-ion battery for self-powered wearable electronics.

Question: What's the cathode?
Answer: Na3V2(PO4)3@C
Novel portable power sources featuring high flexibility, built-in sustainability and enhanced safety have attracted ever-increasing attention in the field of wearable electronics. Herein, a novel flexible self-charging sodium-ion full battery was feasibly fabricated by sandwiching a BaTiO3-P(VDF-HFP)-NaClO4 piezoelectric gel-electrolyte film between an advanced Na3V2(PO4)3@C cathode and hard carbon anode. Besides the considerable flexibility and electrochemical storage performance, the as-designed device also delivers sound self-charging capability via various stress patterns, regardless of whether under static compression, repeated bending or continuous palm patting. Serially connected self-charging devices are able to drive several electronic devices with a good working state. Specifically, a unique theory of electromagnetic fields was successfully introduced to deduce the direct self-charging mechanism, where no rectifier was applied and the battery was charged by the built-in piezoelectric component. This work presents an innovative approach to achieve a new sustainable, safe and flexible sodium-ion battery for self-powered wearable electronics.

Question: What's the anode?
Answer: hard carbon
Novel portable power sources featuring high flexibility, built-in sustainability and enhanced safety have attracted ever-increasing attention in the field of wearable electronics. Herein, a novel flexible self-charging sodium-ion full battery was feasibly fabricated by sandwiching a BaTiO3-P(VDF-HFP)-NaClO4 piezoelectric gel-electrolyte film between an advanced Na3V2(PO4)3@C cathode and hard carbon anode. Besides the considerable flexibility and electrochemical storage performance, the as-designed device also delivers sound self-charging capability via various stress patterns, regardless of whether under static compression, repeated bending or continuous palm patting. Serially connected self-charging devices are able to drive several electronic devices with a good working state. Specifically, a unique theory of electromagnetic fields was successfully introduced to deduce the direct self-charging mechanism, where no rectifier was applied and the battery was charged by the built-in piezoelectric component. This work presents an innovative approach to achieve a new sustainable, safe and flexible sodium-ion battery for self-powered wearable electronics.

Question: What's the electrolyte?
Answer: BaTiO3-P(VDF-HFP)-NaClO4
We have successfully synthesized a self-supported CoFe@NCNT/CFC electrode for mechanically flexible ZABs, through a facile strategy. The optimized CoFe@NCNT/CFC cathode shows excellent bifunctional electrocatalytic activities with a half-wave potential of 0.873 V for the ORR and E10 = 1.506 V for the OER. The flexible all-solid-state ZABs with the CoFe@NCNT/CFC cathode exhibit a large open-circuit voltage of 1.426 V and a large power density of 37.7 mW cm−2 as well as robust stability. More importantly, ZABs assembled with the self-supported CoFe@NCNT/CFC cathode can still work even under extreme bending conditions. Our strategy opens a new way for flexible self-supported catalysts for high-performance portable and rechargeable energy storage devices.

Question: What's the cathode?
Answer: CoFe@NCNT/CFC
Likewise, the cycling performances of bare and coated LMO cathodes were compared using a half-cell (Li|LMO). The cycling performance of the Li|LMO half-cell was examined within the voltage range of 3.3to 4.5 V at 55 °C. The charge and discharge voltage profiles of the bare LMO and surface modified LMO samples (PLMO-10 min, LMO-10 min, and LMO-30 min) are presented in Fig. S3a.† The initial discharge capacity of bare LMO, PLMO-10 min, LMO-10 min, and LMO-30 min are 128.01, 125.42, 127.52, and 130.144 mA h gLMO−1 at 0.3C and 55 °C, respectively. Fig. S3b† displays the cycling performances of all samples measured with the bare LMO and PVDF@LGLZNO fibrous film coated LMO half-cells at 0.3C and 55 °C. The discharge capacity of bare LMO sharply fades to 11 mA h gLMO−1 (9% capacity retention) after 100 cycles, while those of PLMO-10 min, LMO-10 min, and LMO-30 min were 15, 38, and 110 mA h gLMO−1 after 100 cycles at 55 °C and 0.3C, corresponding to capacity retentions of 12.20%, 30.14%, and 83.29%, respectively. Also, the cycling performance of the cell with LMO-50 min at 55 °C and 0.3C is depicted in Fig. S3c.† The above results indicate that LMO-30 min demonstrates better cycling performance at 55 °C compared to other cells, while the bare and PLMO coated cathodes have poor resistance to elevated temperature. The corresponding cells degrade faster than they did at 25 °C as seen in Fig. 2b. The effect of coating on capacity retention at 25 °C and 55 °C is apparent. The optimized PVDF@LGLZNO fibrous film coated on the surface of the LMO electrode acts as a better protective film that could substantially decrease manganese dissolution at high temperatures and minimize the adverse effects caused by electrolyte decomposition.

Question: What's the cathode?
Answer: coated LMO
Likewise, the cycling performances of bare and coated LMO cathodes were compared using a half-cell (Li|LMO). The cycling performance of the Li|LMO half-cell was examined within the voltage range of 3.3to 4.5 V at 55 °C. The charge and discharge voltage profiles of the bare LMO and surface modified LMO samples (PLMO-10 min, LMO-10 min, and LMO-30 min) are presented in Fig. S3a.† The initial discharge capacity of bare LMO, PLMO-10 min, LMO-10 min, and LMO-30 min are 128.01, 125.42, 127.52, and 130.144 mA h gLMO−1 at 0.3C and 55 °C, respectively. Fig. S3b† displays the cycling performances of all samples measured with the bare LMO and PVDF@LGLZNO fibrous film coated LMO half-cells at 0.3C and 55 °C. The discharge capacity of bare LMO sharply fades to 11 mA h gLMO−1 (9% capacity retention) after 100 cycles, while those of PLMO-10 min, LMO-10 min, and LMO-30 min were 15, 38, and 110 mA h gLMO−1 after 100 cycles at 55 °C and 0.3C, corresponding to capacity retentions of 12.20%, 30.14%, and 83.29%, respectively. Also, the cycling performance of the cell with LMO-50 min at 55 °C and 0.3C is depicted in Fig. S3c.† The above results indicate that LMO-30 min demonstrates better cycling performance at 55 °C compared to other cells, while the bare and PLMO coated cathodes have poor resistance to elevated temperature. The corresponding cells degrade faster than they did at 25 °C as seen in Fig. 2b. The effect of coating on capacity retention at 25 °C and 55 °C is apparent. The optimized PVDF@LGLZNO fibrous film coated on the surface of the LMO electrode acts as a better protective film that could substantially decrease manganese dissolution at high temperatures and minimize the adverse effects caused by electrolyte decomposition.

Question: What's the electrolyte?
Answer: LMO
Likewise, the cycling performances of bare and coated LMO cathodes were compared using a half-cell (Li|LMO). The cycling performance of the Li|LMO half-cell was examined within the voltage range of 3.3to 4.5 V at 55 °C. The charge and discharge voltage profiles of the bare LMO and surface modified LMO samples (PLMO-10 min, LMO-10 min, and LMO-30 min) are presented in Fig. S3a.† The initial discharge capacity of bare LMO, PLMO-10 min, LMO-10 min, and LMO-30 min are 128.01, 125.42, 127.52, and 130.144 mA h gLMO−1 at 0.3C and 55 °C, respectively. Fig. S3b† displays the cycling performances of all samples measured with the bare LMO and PVDF@LGLZNO fibrous film coated LMO half-cells at 0.3C and 55 °C. The discharge capacity of bare LMO sharply fades to 11 mA h gLMO−1 (9% capacity retention) after 100 cycles, while those of PLMO-10 min, LMO-10 min, and LMO-30 min were 15, 38, and 110 mA h gLMO−1 after 100 cycles at 55 °C and 0.3C, corresponding to capacity retentions of 12.20%, 30.14%, and 83.29%, respectively. Also, the cycling performance of the cell with LMO-50 min at 55 °C and 0.3C is depicted in Fig. S3c.† The above results indicate that LMO-30 min demonstrates better cycling performance at 55 °C compared to other cells, while the bare and PLMO coated cathodes have poor resistance to elevated temperature. The corresponding cells degrade faster than they did at 25 °C as seen in Fig. 2b. The effect of coating on capacity retention at 25 °C and 55 °C is apparent. The optimized PVDF@LGLZNO fibrous film coated on the surface of the LMO electrode acts as a better protective film that could substantially decrease manganese dissolution at high temperatures and minimize the adverse effects caused by electrolyte decomposition.

Question: What's the cathode?
Answer: PLMO coated
All the electrochemical measurements were carried out on a CHI 660E electrochemical workstation with a standard three-electrode system in 0.5 M aqueous urea solution, and 1 M KOH solution with or without 0.5 M urea at room temperature. A mercury oxide electrode (Hg/HgO), platinum electrode (Pt), and the prepared materials were used as the reference electrode, the counter electrode, and the working electrode, respectively. The mass loading of the catalysts on the nickel foam is 1.5 mg cm−2. And the amount of commercial Pt/C and IrO2 on NF is the same as the loading of MoP@NiCo-LDH/NF-20. The two-electrode electrolyser uses a 007-2H exchangeable membrane electrolytic cell (50 mL) with Nafion 117 as the diaphragm. The synthesized catalysts were used as the cathode and anode electrodes with a distance of 5 cm between the two electrodes. During the test, the anode was connected to the working electrode and the cathode was connected to the counter and reference electrodes. Current densities were calculated based on the geometric area. All potential values were measured on an Hg/HgO electrode and converted to reversible hydrogen potential (RHE) according to the following equation: E (V vs. RHE) = E (V vs. Hg/HgO) + 0.059pH + 0.098 V.

Question: What's the cathode?
All the electrochemical measurements were carried out on a CHI 660E electrochemical workstation with a standard three-electrode system in 0.5 M aqueous urea solution, and 1 M KOH solution with or without 0.5 M urea at room temperature. A mercury oxide electrode (Hg/HgO), platinum electrode (Pt), and the prepared materials were used as the reference electrode, the counter electrode, and the working electrode, respectively. The mass loading of the catalysts on the nickel foam is 1.5 mg cm−2. And the amount of commercial Pt/C and IrO2 on NF is the same as the loading of MoP@NiCo-LDH/NF-20. The two-electrode electrolyser uses a 007-2H exchangeable membrane electrolytic cell (50 mL) with Nafion 117 as the diaphragm. The synthesized catalysts were used as the cathode and anode electrodes with a distance of 5 cm between the two electrodes. During the test, the anode was connected to the working electrode and the cathode was connected to the counter and reference electrodes. Current densities were calculated based on the geometric area. All potential values were measured on an Hg/HgO electrode and converted to reversible hydrogen potential (RHE) according to the following equation: E (V vs. RHE) = E (V vs. Hg/HgO) + 0.059pH + 0.098 V.

Question: What's the anode?
To investigate the electrochemical Na ion storage mechanism on the Na[Ni0.5Mn0.5]O2 and Na0.98Ca0.01[Ni0.5Mn0.5]O2 cathodes upon Na ion extraction/insertion, cyclic voltammetry was performed (Fig. S7†). Both cathodes underwent a series of phase transitions (O3hex. → O′3mon. → P3hex. → P′3mon. → → ). The intensity of the redox peaks of the Na[Ni0.5Mn0.5]O2 cathode, especially during the hexagonal O3′–hexagonal O3′′ phase transition, became gradually polarized and reduced in height with cycling, indicating high capacity fading continuously with structural degradation. In comparison, the redox peaks of the Na0.98Ca0.01[Ni0.5Mn0.5]O2 cathode hardly changed, which is consistent with the excellent Na intercalation stability of the cathode. In addition, ex situ X-ray absorption near edge structure (XANES) analysis was conducted (Fig. 3a and S8†) to examine the oxidation state of transition metals during the charge–discharge process. For both cathodes in the as-prepared state, Ni and Mn were divalent (2+) and tetravalent (4+), respectively. The Ni K-edge absorption spectrum clearly shifted toward the higher energy region after charging at 4.3 V, indicating that a change in the oxidation state of nickel from the divalent state to the tetravalent state occurred due to electrochemical oxidation in the Na cell. In comparison, although a shape change of the white line was observed, which is associated with a local geometry change due to the redox reaction of the surrounding electrochemically active metals, no significant edge shift was observed at the Mn K-edge, suggesting that manganese ions are electrochemically inactive in the tetravalent state, which is consistent with other previous reports. On discharge, the average oxidation state of Ni returned to its original value. Furthermore, this reaction mechanism was also confirmed through prediction of the net magnetic moments on Mn and Ni ions of Nax[Ni0.5Mn0.5]O2 based on first-principles calculations. As presented in Fig. S9,† in the case of O3-Na1[Ni0.5Mn0.5]O2, the integrated spin moments of Ni and Mn atoms were approximately 0 and +3, respectively, which indicates the existence of Ni2+ and Mn4+ ions in O3-Na1[Ni0.5Mn0.5]O2. During 1 mol Na+ extraction from the structure, the integrated spin moment of the Mn atoms remained unaltered and that of the Ni atom gradually increased from 0 to +2, which indicates the Ni2+/Ni4+ redox reaction of O3-Na1[Ni0.5Mn0.5]O2 during Na ion extraction/insertion. This prediction is consistent with the experimental results based on the XANES analysis. These results suggest that 0.01 mol of Ca2+ ions was successfully incorporated into the Na layer rather than a transition metal layer without interrupting the charge-transfer reaction.

Question: What's the cathode?
Answer: Na[Ni0.5Mn0.5]O2
To investigate the electrochemical Na ion storage mechanism on the Na[Ni0.5Mn0.5]O2 and Na0.98Ca0.01[Ni0.5Mn0.5]O2 cathodes upon Na ion extraction/insertion, cyclic voltammetry was performed (Fig. S7†). Both cathodes underwent a series of phase transitions (O3hex. → O′3mon. → P3hex. → P′3mon. → → ). The intensity of the redox peaks of the Na[Ni0.5Mn0.5]O2 cathode, especially during the hexagonal O3′–hexagonal O3′′ phase transition, became gradually polarized and reduced in height with cycling, indicating high capacity fading continuously with structural degradation. In comparison, the redox peaks of the Na0.98Ca0.01[Ni0.5Mn0.5]O2 cathode hardly changed, which is consistent with the excellent Na intercalation stability of the cathode. In addition, ex situ X-ray absorption near edge structure (XANES) analysis was conducted (Fig. 3a and S8†) to examine the oxidation state of transition metals during the charge–discharge process. For both cathodes in the as-prepared state, Ni and Mn were divalent (2+) and tetravalent (4+), respectively. The Ni K-edge absorption spectrum clearly shifted toward the higher energy region after charging at 4.3 V, indicating that a change in the oxidation state of nickel from the divalent state to the tetravalent state occurred due to electrochemical oxidation in the Na cell. In comparison, although a shape change of the white line was observed, which is associated with a local geometry change due to the redox reaction of the surrounding electrochemically active metals, no significant edge shift was observed at the Mn K-edge, suggesting that manganese ions are electrochemically inactive in the tetravalent state, which is consistent with other previous reports. On discharge, the average oxidation state of Ni returned to its original value. Furthermore, this reaction mechanism was also confirmed through prediction of the net magnetic moments on Mn and Ni ions of Nax[Ni0.5Mn0.5]O2 based on first-principles calculations. As presented in Fig. S9,† in the case of O3-Na1[Ni0.5Mn0.5]O2, the integrated spin moments of Ni and Mn atoms were approximately 0 and +3, respectively, which indicates the existence of Ni2+ and Mn4+ ions in O3-Na1[Ni0.5Mn0.5]O2. During 1 mol Na+ extraction from the structure, the integrated spin moment of the Mn atoms remained unaltered and that of the Ni atom gradually increased from 0 to +2, which indicates the Ni2+/Ni4+ redox reaction of O3-Na1[Ni0.5Mn0.5]O2 during Na ion extraction/insertion. This prediction is consistent with the experimental results based on the XANES analysis. These results suggest that 0.01 mol of Ca2+ ions was successfully incorporated into the Na layer rather than a transition metal layer without interrupting the charge-transfer reaction.

Question: What's the cathode?
Answer: Na0.98Ca0.01[Ni0.5Mn0.5]O2
As the key component in HZBs, cathodes work as the electroactive materials in rechargeable Zn-ion batteries and the catalyst in Zn–air batteries. They link both electrochemical reactions at the same time and have attracted great interest. Lee et al. initially prepared NiO/Ni(OH)2 nanoflakes on carbon paper as cathodes for HZBs, which opens the door for hybrid zinc systems. M. Ni's group and Zhi's group prepared Co3O4 nanosheets on carbon cloth to fabricate a Zn–Co3O4/air hybrid battery. Wang et al. constructed NiCo2S4 nanotubes on an N-doped carbon network derived from filter paper and fabricated a Zn–NiCo2S4/air hybrid battery with high capacity. Li et al. used NiCo2O4 nanorod@carbon coated nickel foam as the cathode to build a hybrid battery which exhibited good stability. Tan et al. prepared a Zn–Ag/air hybrid battery and achieved good reversibility and stability. Very recently, Zhi's group reported Ni3S2 nanosheets on Ni foam as a high-performance HZB cathode. Although rapid developments have been made for HZBs, defects such as slow oxygen reduction/evolution reactions (ORR/OER) and inferior energy storage properties still limit their practical applications. Therefore, it is still a crucial issue to explore novel cathode candidates for HZBs to realize both high efficiency and high energy storage properties at the same time.

Question: What's the cathode?
Answer: NiCo2O4 nanorod@carbon coated nickel foam
As the key component in HZBs, cathodes work as the electroactive materials in rechargeable Zn-ion batteries and the catalyst in Zn–air batteries. They link both electrochemical reactions at the same time and have attracted great interest. Lee et al. initially prepared NiO/Ni(OH)2 nanoflakes on carbon paper as cathodes for HZBs, which opens the door for hybrid zinc systems. M. Ni's group and Zhi's group prepared Co3O4 nanosheets on carbon cloth to fabricate a Zn–Co3O4/air hybrid battery. Wang et al. constructed NiCo2S4 nanotubes on an N-doped carbon network derived from filter paper and fabricated a Zn–NiCo2S4/air hybrid battery with high capacity. Li et al. used NiCo2O4 nanorod@carbon coated nickel foam as the cathode to build a hybrid battery which exhibited good stability. Tan et al. prepared a Zn–Ag/air hybrid battery and achieved good reversibility and stability. Very recently, Zhi's group reported Ni3S2 nanosheets on Ni foam as a high-performance HZB cathode. Although rapid developments have been made for HZBs, defects such as slow oxygen reduction/evolution reactions (ORR/OER) and inferior energy storage properties still limit their practical applications. Therefore, it is still a crucial issue to explore novel cathode candidates for HZBs to realize both high efficiency and high energy storage properties at the same time.

Question: What's the cathode?
Answer: Ni3S2 nanosheets on Ni foam