Aromatic Compounds as Redox Shuttle Additives for 4 V Class Secondary Lithium Batteries

Overcharge Protection for Rechargeable Lithium Batteries Using Electroactive Polymers

“…Redox shuttle additives can provide an internal, automatic overcharge protection mechanism that allows charging current to pass through a cell without overcharging it. [2][3][4][5] However, their ability to carry useful overcharge currents is limited by their low diffusion coefficients relative to that of lithium ion. Polymerization ͑or shutdown͒ additives, which make cells resistive by forming insulating polymers upon overcharging or actuate pressure disconnects by generating gases, are attractive only for small batteries where it is practical to remove a damaged cell from operation and replace it.…”

Redox Shuttle Additives for Lithium-Ion Battery

“…14 Around the same time, Adachi and co-workers conducted a screening study, investigating a series of metallocene and dimethoxybenzene (5-8 in Figure 2) derivatives. 15 Metallocene compounds were observed to be electrochemical reversible systems with potentials around 4 V, but the low solubility and large molecular size hindered their overcharge performance in electrolytes. Dimethoxybenzene derivatives, on the other hand, did show promising results, especially for those compounds with methoxy groups at the ortho and para positions.…”

Xylene as a New Polymerizable Additive for Overcharge Protection of Lithium Ion Batteries

“…[16][17][18][19][20] Redox additives were firstly reported to operate as a redox couple shuttling between the cathode and anode to shunt charging current. 21,22 However, the additives reported so far do not operate effectively at required charging rates because of their poor solubility and low diffusion coefficients in the organic electrolyte. Another kind of additive for overcharge protection is polymerizable compounds, also called "shutdown additives", which can be electrochemically polymerized at an overcharged cathode.…”