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Abstract: A polytriphenylamine (PTPAn)-modified separator was prepared simply by impregnating triphenylamine monomers into a commercial Celgard separator and in situ polymerizing the monomers into electroactive phase by oxidant ozone. This type of electroactive separator can transform from an insulating state to a conductive state at overcharged voltage of ∼3.7V (vs. Li+/Li) and act as a self-actuating potential-switchable separator for overcharge protection of LiFePO4/C Li-ion batteries. The experimental results demonstrated that this electroactive separator can reversibly control the cell''s voltage at the safe value less than 4.15V at high rate overcharge of 2C current without obvious negative impact on the normal charge–discharge performances of the commercial LiFePO4/C batteries even at prolonged overcharge cycling, showing a potential application in 3.6V-class lithium-ion batteries. [Copyright &y& Elsevier]

A high capacity and cycle-stable organic molecule/polymer composite is synthesized by physical doping of redox-active perylene-3,4,9,10-tetracarboxydiimide (PTCDI) in polypyrrole (PPy). The as-prepared PTCDI/PPy composite demonstrates a synergistic electrochemical activation, in which the insoluble large PTCDI anions act as a redox-active dopant to activate the PPy backbones, while the activated PPy backbones form a conductive network to promote the redox activity of PTCDI molecules for Li insertion/extraction reactions. As a result, the PTCDI/PPy composite demonstrated a considerably high reversible capacity of >100 mAh g −1 and a stable cyclability with 92% capacity retention over 200 cycles, possibly serving as a low cost and renewable alternative to the inorganic cathode materials for Li-ion batteries. Since such a physical doping method is simple and easily adoptable for different organic molecules and polymers, it may offer a new route for developing low cost and electrochemically active organic electrode materials. [ABSTRACT FROM AUTHOR]

Abstract: Rechargeable batteries using organic materials have potential advantages of low cost and materials sustainability for large-scale electric storage applications. The key issue to realize such sustainable batteries is to develop suitable organic electrode materials with sufficient redox capacity and cycling stability. Herein, we introduce lithium and sodium salt of 3, 4, 9,10-perylenetetracarboxylic acid (Li4C24H8O8, Na4C24H8O8) as new organic anode materials for Li-ion and Na-ion batteries. The Li4C24H8O8 electrode can deliver a reversible capacity of ∼200mAhg−1 at quite low charge/discharge plateaus of 1.20/1.10V, and remains 98% of its initial capacity after 100 cycles. Similarly, the Na4C24H8O8 electrode exhibits a reversible Na storage capacity of ∼100mAhg−1 at a low voltage region of 0.8–0.6V (vs Na) with almost indiscernible capacity decay during 100 cycles. These results demonstrate a potential possibility to use the organic anodes for Li-ion and Na-ion batteries. [Copyright &y& Elsevier]

Abstract: All-organic rechargeable batteries may have low cost, materials sustainability and environmental friendliness, particularly suitable for large scale electric energy storage applications. However, development of such a new generation of batteries is now hindered by the lack of appropriate organic anode materials. In this paper, we report a novel polythiophene/carbon composite, where n-dopable poly (3,4-dihexylthiophene) is in situ chemically polymerized on carbon nanofibers. This organic-carbon composite exhibits an exceptionally high reversible electrochemical capacity of ∼300mAhg−1 (or ∼ 200AhL−1) through n-type redox reactions and superior capacity retention of ⩾95% after a hundred cycles. Based on this n-type redox-active material, an all-organic Li-ion cell using polytriphenylamine as cathode-active material was constructed and found to operate successfully, demonstrating possible applications of this composite as a high capacity anode material for all-organic storage batteries. [Copyright &y& Elsevier]

Abstract: A voltage-sensitive separator is prepared simply by impregnating electroactive poly(3-decylthiophene) (P3DT) polymer into a commercial porous separator and tested for a self-actuating control of overcharge voltage of LiFePO4/C lithium-ion batteries. The experimental results demonstrate that this type of separator can be reversibly p-doped and dedoped to maintain the cell''s voltage at a safe value of ≤4V even at high rate overcharge of 3C current, effectively protecting the batteries from voltage runaway. Since this P3DT-modified separator has no obvious negative impact on the normal charge–discharge performance of the batteries, it may be adopted for practical application in commercial lithium ion batteries. [Copyright &y& Elsevier]

Abstract: A novel compound, tri-(4-methoxythphenyl) phosphate, was synthesized and investigated as a safety electrolyte additive for lithium-ion batteries. It was found that this additive could lower the flammability of the electrolyte, and thereby enhance the thermal stability of the Li-ion battery. Moreover, this molecule can also be polymerized at 4.35V (vs. Li/Li+) to form a conducting polymer, which can protect the batteries from voltage runaway at overcharge by internal bypassing the overcharging current in the batteries. Thus, it is possible to use this electrolyte additive to provide both overcharge protection and flame retardancy for lithium-ion batteries without much influence on the battery performance. [Copyright &y& Elsevier]

Abstract: A new fire retardant-dimethyl methyl phosphate (DMMP) was tested as a nonflammable electrolyte solvent for Li-ion batteries. It is found that in the addition of chloro-ethylene carbonate (Cl-EC) as an electrolyte additive, the electrochemical reduction of DMMP molecules can be completely suppressed and the graphite anode can be cycled very well with high initial columbic efficiency (∼84%) and excellent cycling stability in the DMMP electrolyte. The prismatic C/LiCoO2 batteries using 1.0molL−1 LiClO4 +10% Cl-EC+DMMP electrolyte exhibited almost the same charge and discharge performances as those using conventional carbonate electrolytes, suggesting a feasible use of this new electrolyte for constructing nonflammable Li+-ion batteries. [Copyright &y& Elsevier]