Understanding the redox shuttle stability of 3,5-di-tert-butyl-1,2-dimethoxybenzene for overcharge protection of lithium-ion batteries

Redox Shuttle Additives for Lithium-Ion Battery

“…Third, the electrochemical stability is of vital importance in determining the longevity of overcharge protection resulting from redox shuttles. 20,21,23,28 This stability actually depends upon the stability of the oxidative species (S + in Figure 1) of the redox shuttles generated during overcharge protection. However, evaluation of redox shuttle stability does not have a clear standard.…”

“…28 The compatibility can be determined for many different properties relative to different cell components. For instance, for the compatibility of the redox shuttle to the electrolyte solutions, the effects of redox shuttle solubility, conductivity, co-reaction, etc., have to be investigated and considered.…”

“…It is built on the benzene ring with two methoxy groups helping to stabilize the radical cation that could be produced during the overcharge process, and two tert-butyl groups were attached to the benzene ring to protect the radical cation from intermolecular annihilation. 20,28 With this design, DDB displays perfect electrochemical reversibility at 3.9 V vs. Li/Li + and provides over 200 cycles of overcharge protection to the lithium-ion cells using LiFePO 4 cathodes. DDB meets most of the aforementioned characteristics in terms of overcharge performance and is very close to practical application.…”

“…Overcharge generally occurs when a current is forced through a cell, and the charge delivered exceeds its charge-storing capability. [1][2][3] Overcharge of lithium-ion batteries can lead to the chemical and electrochemical reaction of batteries components, rapid temperature elevation, self-accelerating reactions, and even explosion. Redox shuttle additives have been proposed for overcharge protection of secondary lithiumion batteries for decades.…”

A positive-temperature-coefficient electrode with thermal protection mechanism for rechargeable lithium batteries

“…To seek for a better safety control, much effort has been focused on the development of internal and self-actuating safety mechanisms for Li-ion batteries. Several strategies, including redox shuttles [16,17], polymerizable monomers [18], and potential-sensitive separators [19], have been devised to improve safety under overcharge condition, but they work only at high charging voltages and actually do not respond to heat generation in batteries. Although the polyolefin microporous separator membranes commonly used in Li-ion batteries have thermal shutdown characteristics [20], they cannot retain mechanical integrity above their shutdown temperature generally.…”