In situ detection of reactive oxygen species spontaneously generated on lead acid battery anodes: a pathway for degradation and self-discharge at open circuit

Abstract

Prospects for refurbishing and recycling energy storage technologies such as lead acid batteries (LABs) prompt a better understanding of their failure mechanisms. LABs suffer from a high self-discharge rate accompanied...

Real-time investigation of reactive oxygen species and radicals evolved from operating Fe–N–C electrocatalysts during the ORR: potential dependence, impact on degradation, and structural comparisons

“…In this work, we report the use of a scanning electrochemical microscopy (SECM) technique that our group has recently developed for the detection and quantification of transient radical species in real time. 59,60 SECM is an electrochemical scanning probe technique that positions an ultramicroelectrode (UME) tip over a substrate to achieve high spatial and temporal resolution and to collect substrate-generated species near the source. 61,62 These attributes are excellent for the detection and quantification of short-lived reactive intermediates and radical species.…”

“…69 Similarly, this SG/TC configuration can be used to detect hydrogen peroxide if a platinum UME is used to catalytically oxidize H 2 O 2 , similar to the use of a platinum ring in the RRDE (Scheme 1B). 60,70–72 Here we use these SECM techniques to comprehensively investigate the generation of ROS by a commercial pyrolyzed Fe–N–C catalyst (Pajarito Powder) as well as several model systems, such as iron phthalocyanine, which have been reported to be superior ORR electrocatalysts. 73–75 We demonstrate the ability to measure radical formation as a result of the ORR process in different amounts at these catalytic surfaces.…”