Amphiphilic Graft Copolymers as a Versatile Binder for Various Electrodes of High-Performance Lithium-Ion Batteries

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• 作者：Jung-In Lee ; Hyojin Kang ; Kwang Hyun Park ; Myoungsoo Shin ; Dongki Hong ; Hye Jin Cho ; Na-Ri Kang ; Jungho Lee ; Sang Myeon Lee ; Ju-Young Kim ; Choon Ki Kim ; Hyesung Park ; Nam-Soon Choi ; Soojin Park and Changduk Yang
• 刊名：Small
• 出版年：2016
• 出版时间：June 15, 2016
• 年：2016
• 卷：12
• 期：23
• 页码：3119-3127
• 全文大小：1660K
• ISSN：1613-6829

文摘

It is known that grafting one polymer onto another polymer backbone is a powerful strategy capable of combining dual benefits from each parent polymer. Thus amphiphilic graft copolymer precursors (poly(vinylidene difluoride)-graft-poly(tert-butylacrylate) (PVDF-g-PtBA)) have been developed via atom transfer radical polymerization, and demonstrated its outstanding properties as a promising binder for high-performance lithium-ion battery (LIB) by using in situ pyrolytic transformation of PtBA to poly(acrylic acid) segments. In addition to its superior mechanical properties and accommodation capability of volume expansion, the Si anode with PVDF-g-PtBA exhibits the excellent charge and discharge capacities of 2672 and 2958 mAh g⁻¹ with the capacity retention of 84% after 50 cycles. More meaningfully, the graft copolymer binder shows good operating characteristics in both LiN_0.5M_1.5O₄ cathode and neural graphite anode, respectively. By containing such diverse features, a graft copolymer-loaded LiN_0.5M_1.5O₄/Si-NG full cell has been successfully achieved, which delivers energy density as high as 546 Wh kg⁻¹ with cycle retention of ≈70% after 50 cycles (1 C). For the first time, this work sheds new light on the unique nature of the graft copolymer binders in LIB application, which will provide a practical solution for volume expansion and low efficiency problems, leading to a high-energy-density lithium-ion chemistry.