Mixed gel electrolytes: Synthesis, characterization, and gas release on PbSb electrode

Abstract

Mixed gel electrolytes were fabricated chemically at a temperature range of 2–5°C using some additives comparing with traditional electrolytes (1.26 g/cm3 H2SO4). The polyacrylamide (PAM) content is kept constant (0.2 wt%), while the propylene glycol (PPG) and nano fumed silica (NFS) contents varied. The material characteristics of samples were assessed by physical appearance observation, electrochemical measurements, and physicochemical methods. The results showed that a hard gel without separation of solutions was found in the case using a PAM/PPG/NFS ternary additive (0.2/0.1/0.6 wt%). The morphological structure (<50 nm) of mixed gel electrolytes was in the range of nanometer. The gas release on the PbSb electrode was strongly inhibited (92.2–93.7% for O2 and ∼55% for H2 at the 120th cycle), which will both contributes to reducing the pressure as well as limiting water loss in the sealed lead acid battery, compared with that in the sulfuric acid medium.

Keywords

• mixed gel electrolyte
• additives
• ionic conductivity
• diffusion coefficient
• gas release