The passive cotton-based Al-air battery adopts the cotton cloth as the flow channel to transport the electrolyte by the capillary force from the cloth. An absorbent pad is usually put at the end of the cotton cloth to keep the electrolyte continuously flowing. Once the absorbent pad is saturated, the electrolyte flow slows down or even stops. This can affect the transportation of the electrolyte and product, decreasing the battery performance. To maintain the electrolyte's continuous flow, the cotton-based Al-air battery with the tilt angle was presented and constructed. The effects of the catalyst loadings, tilt angles, electrolyte types, and area ratios on this battery were studied. Under the 4 mg cm(-2 )carbon catalyst loading, 10 degrees tilt angle, 4 mol L-1 KOH electrolyte, and anode-to-cathode area ratio of 1 : 3, this battery performance was optimal, with the peak power density of 78.09 +/- 0.68 mW cm(-2) and limiting current density of 213.12 +/- 0.80 mA cm(-2). Finally, the battery stack was gained by connecting the two batteries with the 10 degrees tilt angle in series. This stack with a peak power of 48.47 +/- 0.37 mW could light the 44 LEDs.

为获得一种高性能且低成本的新型水系铝电池,本文提出并构建了一种直接铝-过硫酸钠微流体燃料电池.研究了阳极电解液浓度、阴阳极电解液总流速及其流速比、氧化剂浓度对该微流体燃料电池产电性能的影响.结果表明:当阳极电解液浓度为2.00 mol/L,阴阳极电解液总流速为200μL/min,阴阳极电解液流速比为1:1,过硫酸钠氧化剂浓度为1.5 mol/L时,该直接铝-过硫酸钠微流体燃料电池的产电性能达到最佳,其开路电压为2.56 V,功率密度和电流密度的最大值分别为275 mW/cm2和216 mA/cm2,铝阳极的最大比容量密度达到2760 mAh/g.

Conventional Al-air batteries are not suitable as portable power devices due to their complicated water management and bulky system. To resolve this issue, the fiber paper- and cotton cloth-based Al-air batteries were proposed, which exploited the capillary force from the paper (FP) and cotton cloth (CC) to deliver the solutions and eliminated the external pump. The physical features of the FP and CC were gained including the surface morphologies, surface elementary analysis, liquid absorption and flow rates. CC owned larger liquid absorption and faster flow rate due to its hierarchically woven-spun fiber structure, compared to the randomly oriented fibers of the FP, although the surface of the CC demonstrated lower O/C ratio than that of the FP. So, the performance of the CC-based Al-air battery was largely higher than that of the FP-based battery. The performance of the CC-based Al-air battery was optimal at 1.0 M NaOH electrolyte and the anode-to-cathode surface area ratio of 1 : 4, with the peak power density of 14.95 & PLUSMN;0.28 mW cm(-2), and the maximum current density of 36.61 & PLUSMN;0.54 mA cm(-2). To apply the CC-based Al-air battery, the two-battery pack connected in series was assembled to drive a timer and light 9 LEDs.

The cotton‐based metal–air batteries without any catalyst are constructed. Especially, the continuous electrolyte flowing depends on the capillary force and the gravity from the height difference between the inlet and outlet. The performance of the cotton‐based metal–air batteries under 2 mol L −1 NaOH or NaCl solutions is compared. The Al–air battery performance in the NaOH solution is better, while the Mg–air battery performance in the NaCl solution is the best. Considering the battery performance and cost, the alkaline cotton‐based Al–air battery is investigated for the subsequent experiments. The Al–air battery performance is evaluated under the different cotton cloth makeups, NaOH concentrations, height differences between the inlet and outlet. The results show that under the conditions of the cotton makeup (20 (warp) × 60 (yarn)), 4 mol L −1 NaOH and 60 mm height difference, the battery performance is optimal, with the peak power density of 12.33 ± 0.38 mW cm −2 and limiting current density of 35.28 ± 0.73 mA cm −2 . To apply the cotton‐based Al–air battery, the two‐battery stack connected in series powers 15 light‐emitting diodes. The experiments demonstrate the cotton‐based Al–air battery without catalysts owns low cost and high power output, which has great potential as a micropower device.