A document by Yun Zhao. Click on the document to view its contents.

Lead-acid battery system is designed to perform optimally at ambient temperature (25 °C) in terms of capacity and cyclability. However, varying climate zones enforce harsher conditions on the automotive lead acid batteries. Hence, they age faster and exhibit low performance when operated at either extremity of the optimum ambient conditions. In this work, a systematic study was conducted to analyze the effect of varying temperatures (-10, 0, 25 and 40 °C) on the sealed lead acid. Enersys® Cyclon (2V, 5Ah) cells were cycled at C/10 rate using battery testing system. The environmental aging results in shorter cycle life due to the degradation of electrode, and grid materials at higher temperature (25 and 40 °C), while at lower temperature (-10 and 0 °C) negligible degradation was observed due to slower kinetics and reduced available capacity. Electrochemical impedance spectroscopy, X-ray diffraction and Energy-dispersive X-ray spectroscopy analysis were used to evaluate the degradation mechanism, chemical and morphological changes.

The design and fabrication of flexible, porous, conductive electrodes with customizable functions become the prime challenge in the development of new-generation wearable electronics, especially for rechargeable batteries. Here, NiCo bi-alloy particulate catalysts loaded self-supporting carbon foam framework (NiCo@SCF) as a flexible electrode has been fabricated through one facile adsorption-pyrolysis method using a commercial melamine foam. Compared with the electrode with Pt/C and Ir/C benchmark catalysts, the NiCo@SCF electrode exhibited superior bifunctional electrocatalytic performance in alkaline media with a half-wave potential of 0.906V for oxygen reduction reaction, an overpotential of 286 mV at j=10 mA cm−2 for oxygen evolution reaction, and stable bifunctional performance with a small degradation after 20,000 voltammetric cycles. The as-assembled aqueous zinc-air battery (ZAB) with NiCo@SCF as a self-supporting air cathode demonstrated a high peak power density of 178.6 mW cm-2 at a current density of 10 mA cm−2 and a stable voltage gap of 0.94V a 540 h charge-discharge operation. Remarkably, the as-assembled flexible solid-state ZAB with self-supporting NiCo@SCF as air cathode presented an engaging peak power density of 80.1 mW cm-2 and excellent durability of 95 h undisrupted operation, showing promise for the design of wearable ZAB.