A chelating-agent-assisted Na2/3Fe1/2Mn1/2O2 material showed enhanced electrochemical performance due to the formation of a thin and stable solid-electrolyte interface layer.
Driven by a paradigm shift from conventional liquid-based systems to all-solid-state batteries (ASSBs), the chemo-mechanical behavior of the solid–solid interface is of growing importance for understanding the intricate interfacial phenomena of ASSBs.
The electrochemical behaviors of a silicon thin-film electrode in organic lithium salt solution were explored with focus on irreversible reactions of the first lithium charge and discharge cycling by using electrochemical quartz crystal microbalance ͑EQCM͒ combined with various electrochemical techniques. A considerable increase in mass of the silicon electrode was observed during lithium charging even before lithium absorption into the electrode, which is ascribed to the buildup of electrolyte reduction products on the silicon surface. Galvanostatic charge-discharge experiments combined with ac impedance spectroscopy demonstrate a significant overpotential growth and an aggravating capacity for the lithium charge and discharge cycling, and suggest they are due to the sedimentation of electrolyte reduction product. Additives containing alkoxy silane functional groups were evaluated as a passivation agent for lithium rechargeable batteries utilizing a silicon anode. The presence of additives in electrolyte suppressed the mass accumulation to the silicon electrode caused by irreversible electrolyte reductions and improved the electrode for cycle life. Electrochemical analyses associated with EQCM as a function of the number of alkoxy functional groups of the additives illustrate that the silicon electrode is passivated by chemical reaction of the alkoxy silane functional group of the additives with hydroxyl groups at the electrode/electrolyte interface, and this passivation improves the cycle life.Silicon as a negative electrode for lithium-ion batteries has been attracting significant interest because of its high specific capacity. 1-6 Silicon reacts with lithium to form Li 4.4 Si alloy, showing theoretical capacity of 4200 mAh/g. Capacity retention is the most important issue for utilizing the silicon-based negative electrode. 1,2,4 It has been generally accepted that the limited cycle life of the silicon electrode is ascribed to severe volume changes of the electrode. 5,6 Many researchers have focused on the structural modification of the silicon electrode to prolong the cycle life of the electrode. 3,4,6 In crystalline silicon, intermetallic phases are formed during lithium charging, leading to inhomogeneous volume expansions which can cause cracking and pulverization of the silicon-lithium alloy. 3,5 Reversible lithium cycling with little capacity loss is possible for amorphous silicon thin film in which the homogeneous volume expansion occurs. 5 To suppress the volume expansion during lithium charging, the silicon particle of the fine grain size uniformly distributed within a less active matrix, like graphite, has been proposed. 7 Organic lithium salt solution reduces electrochemically on the silicon electrode to form a solid electrolyte interphase layer on the electrode because the lithiation potential of the silicon electrode is far lower than 1.0 V Li/Li + . However, few studies on the interface between silicon electrode and organic electrolyte have been conducted. Unlike graphite electrode, it is reasonab...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.