In this study, the Lewis doping approach of polyaniline (PANI) was employed to fabricate cobait–nitrogen–carbon (Co–N–C) oxygen electrocatalysts for Zn–air batteries, aiming to enhance the active spots of Co–N–C. This resulting Co–N–C catalysts exhibited well-defined nanofiber networks, and the Brunauer-Emmett-Teller (BET) analysis confirmed their substantial specific surface area. Electrochemical experiments demonstrated that the Co–N–C catalysts achieved the half-wave potential (vs. RHE) of 0.85 V in alkaline medium, overcoming Pt/C and iron–nitrogen–carbon (Fe–N–C) counterparts in extended cycle testing with only a 25 mV change in a half-wave potential after 5000 cycles. Remarkably, the highest power density measured in the zinc (Zn)-air battery reached 227 mW/cm², a significant improvement over the performance of 101 mW/cm² of the platinum on activated carbon (Pt/C) catalyst. These findings highlight the advantageous stability enhancement associated with the utilization of Co in the Co–N–C catalysts.

In modern alkaline batteries, the zinc anode is the performance-limiting and lifetime-limiting electrode, making the choice of zinc powder critical. Due to the various material fabrication processes that are used to manufacture industrial zinc powder, there exists a wide array of possible zinc particle shapes, sizes, and crystallinities. These industrial zinc powders are typically conceived, produced, and tested through trial-and-error processes using historical “rules of thumb.” However, a data-driven approach could more effectively elucidate the optimum combination of zinc particle properties. In this paper, the effect of Zn particle size, shape, and crystallinity on the achievable capacity and corrosion current is investigated. The Zn types are tested in both powder and slurry form. Following the data collection, a factorial-based statistical analysis is performed to determine the most statistically significant variables affecting capacity and corrosion. This information is then used to down-select to a subset of particles that are tested in cylindrical cells with an AA-equivalent geometry. The reported technique can be used to develop actionable principles for battery manufacturers to create cells that are more stable, longer lasting, and have higher energy densities.

Due to the depletion of traditional fossil fuels and the aggravation of related environmental problems, hydrogen energy is gaining more attention all over the world. Solid oxide fuel cell (SOFC) is a promising power generation technology operating on hydrogen with a high efficiency. To further boost the power output of a single cell and thus a single stack, increasing the cell area is an effective route. However, it was recently found that further increasing the effective area of an SOFC single cell with a flat-tubular structure and symmetric double-sided cathodes would result in a lower areal performance. In this work, a multi-physical model is built to study the effect of the effective area on the cell performance. The distribution of different physical fields is systematically analyzed. Optimization of the cell performance is also pursued by systematically tuning the cell operating condition and the current collection setup. An improvement of 42% is revealed by modifying the inlet gas flow rates and by enhancing the current collection. In the future, optimization of cell geometry will be performed to improve the homogeneity of different physical fields and thus to improve the stability of the cell.

Exploring cathode materials that combine excellent cycling stability and high energy density poses a challenge to aqueous Zn-ion hybrid supercapacitors (ZHSCs). Herein, polyaniline (PANI) coated boron-carbon-nitrogen (BCN) nanoarray on carbon cloth surface is prepared as advanced cathode materials via simple high-temperature calcination and electrochemical deposition methods. Because of the excellent specific capacity and conductivity of PANI, the CC@BCN@PANI core-shell nanoarrays cathode shows an excellent ion storage capability. Moreover, the 3D nanoarray structure can provide enough space for the volume expansion and contraction of PANI in the charging/discharging cycles, which effectively avoids the collapse of the microstructure and greatly improves the electrochemical stability of PANI. Therefore, the CC@BCN@PANI-based ZHSCs exhibit superior electrochemical performances showing a specific capacity of 145.8 mAh/g, a high energy density of 116.78 Wh/kg, an excellent power density of 12 kW/kg, and a capacity retention rate of 86.2% after 8000 charge/discharge cycles at a current density of 2 A/g. In addition, the flexible ZHSCs (FZHSCs) also show a capacity retention rate of 87.7% at the current density of 2 A/g after 450 cycles.

Aqueous zinc-ion batteries (ZIBs) have great prospects for widespread application in massive scale energy storage. By virtue of the multivalent state, open frame structure and high theoretical specific capacity, vanadium (V)-based compounds are a kind of the most developmental potential cathode materials for ZIBs. However, the slow kinetics caused by low conductivity and the capacity degradation caused by material dissolution still need to be addressed for large-scale applications. Therefore, sodium vanadate Na₂V₆O₁₆·3H₂O (NVO) was chosen as a model material, and was modified with alumina coating through simple mixing and stirring methods. After Al₂O₃ coating modification, the rate capability and long-cycle stability of Zn//NVO@Al₂O₃ battery have been significantly improved. The discharge specific capacity of NVO@Al₂O₃ reach up to 228 mAh/g (at 4 A/g), with a capacity reservation rate of approximately 68% after 1000 cycles, and the Coulombic efficiency (CE) is close to 100%. As a comparison, the capacity reservation rate of Zn//NVO battery is only 27.7%. Its superior electrochemical performance is mainly attributed to the Al₂O₃ coating layer, which can increase zinc-ion conductivity of the material surface, and to some extent inhibit the dissolution of NVO, making the structure stable and improving the cyclic stability of the material. This paper offers new prospects for the development of cathode coating materials for ZIBs.