电压敏感性隔膜用于锂离子电池可逆过充保护

A Potential-Sensitive Separator Capable of Providing a Reversible Overcharge Protection for Lithium Ion Batteries

研制了一种具有电压敏感功能并可为4.20 V级锂电池和锂离子电池提供可逆过充保护的新型复合聚合物膜.这种膜由聚对苯(PPP)和聚苯胺(PAn)膜复合而成,在无掺杂的本征状态下为电子绝缘体;在高的氧化电势下因发生p-掺杂而变成电子导体;在正常工作电压下又因脱杂而恢复成电子绝缘体.因而,它可以作为一种电压敏感性隔膜用于防止电池过充.在Li/LiMn2O4模拟电池中的应用研究结果证实,在长时间的过充条件下,这种复合隔膜仍能够有效地钳制电池的充电电压,从而为电池提供可逆的过充保护.在正常充放电条件下,复合隔膜对电池性能没有产生负面影响.

A composite electroactive polymer membrane capable of providing a reversible self-activating current shunt for overcharge protection of 4. 20 V class lithium batteries and lithium ion batteries was described. The membrane is composed of a p-polyphenyl （PPP） layer and a polyaniline （PAn） layer, and can be p doped at high oxidation potentials of 4.30 V into conductive phase and de-doped at normal operating voltages into an electronically isolating separator, functioning as a potential-sensitive switch for controlling the battery voltage at charging. The experimental results from the laboratory Li/LiMn2O4 cells demonstrate that this composite membrane can reversibly control the battery voltage at required value at prolonged overcharge and has no negative impact on the battery performances at normal charge discharge conditions.