{"title":"统一的全孔微观结构使隔膜具有超高孔隙率,可用于坚固的高通量锂电池","authors":"Dongjiang Chen, Yuanpeng Liu, Chao Feng, Yuhui He, Shengyu Zhou, Botao Yuan, Yunfa Dong, Haodong Xie, Guangfeng Zeng, Jiecai Han, Weidong He","doi":"10.1002/elt2.1","DOIUrl":null,"url":null,"abstract":"<p>With small thickness, commercial polyolefin separators own low porosity to ensure sufficient thermomechanical properties, resulting in tortuous and enlarged Li<sup>+</sup> diffusion pathways that induce large overpotentials and detrimental dendrite growth. As a dilemma, the exploration of highly porous separators has been challenged by their large thickness, impairing the applicability of such pursuits. Herein, an ultraporous architecture is designed to shorten Li<sup>+</sup> transfer pathways by impregnating electrolyte-affinitive poly (vinylidene fluoride-co-hexafluoropropylene) into ultralight ∼3 μm 3D-polytetrafluoroethylene scaffold (abbreviated as UP3D). The UP3D separator with a porosity of 74% gives rise to 70% enhancement in Li<sup>+</sup> transference and 77% reduction in Li<sup>+</sup> transfer resistance (2.67 mΩ mm<sup>−1</sup>) and thus enables an ultrahigh Li<sup>+</sup> flux of 22.7 mA cm<sup>−2</sup>, effectively alleviating Li<sup>+</sup> concentration gradient across the separator. With the separator, the LiFePO<sub>4</sub> half cell delivers a capacity of 118 mAh g<sup>−1</sup> with an unparalleled capacity retention of 90% after 1000 cycles at 2 C, and a graphite || LiNi<sub>0.6</sub>Co<sub>0.2</sub>Mn<sub>0.2</sub>O<sub>2</sub> pouch full cell delivers an areal energy density of 6.8 mWh cm<sup>−2</sup> at 8.848 mA (1.4 mA cm<sup>−2</sup>) with a high cathode loading of 134.9 mg. Such results, together with the scalable production of the separator, reflect its promising potential in high-flux battery applications of separators that require both ultrahigh porosity and reliability.</p>","PeriodicalId":100403,"journal":{"name":"Electron","volume":"1 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/elt2.1","citationCount":"1","resultStr":"{\"title\":\"Unified throughout-pore microstructure enables ultrahigh separator porosity for robust high-flux lithium batteries\",\"authors\":\"Dongjiang Chen, Yuanpeng Liu, Chao Feng, Yuhui He, Shengyu Zhou, Botao Yuan, Yunfa Dong, Haodong Xie, Guangfeng Zeng, Jiecai Han, Weidong He\",\"doi\":\"10.1002/elt2.1\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>With small thickness, commercial polyolefin separators own low porosity to ensure sufficient thermomechanical properties, resulting in tortuous and enlarged Li<sup>+</sup> diffusion pathways that induce large overpotentials and detrimental dendrite growth. As a dilemma, the exploration of highly porous separators has been challenged by their large thickness, impairing the applicability of such pursuits. Herein, an ultraporous architecture is designed to shorten Li<sup>+</sup> transfer pathways by impregnating electrolyte-affinitive poly (vinylidene fluoride-co-hexafluoropropylene) into ultralight ∼3 μm 3D-polytetrafluoroethylene scaffold (abbreviated as UP3D). The UP3D separator with a porosity of 74% gives rise to 70% enhancement in Li<sup>+</sup> transference and 77% reduction in Li<sup>+</sup> transfer resistance (2.67 mΩ mm<sup>−1</sup>) and thus enables an ultrahigh Li<sup>+</sup> flux of 22.7 mA cm<sup>−2</sup>, effectively alleviating Li<sup>+</sup> concentration gradient across the separator. With the separator, the LiFePO<sub>4</sub> half cell delivers a capacity of 118 mAh g<sup>−1</sup> with an unparalleled capacity retention of 90% after 1000 cycles at 2 C, and a graphite || LiNi<sub>0.6</sub>Co<sub>0.2</sub>Mn<sub>0.2</sub>O<sub>2</sub> pouch full cell delivers an areal energy density of 6.8 mWh cm<sup>−2</sup> at 8.848 mA (1.4 mA cm<sup>−2</sup>) with a high cathode loading of 134.9 mg. Such results, together with the scalable production of the separator, reflect its promising potential in high-flux battery applications of separators that require both ultrahigh porosity and reliability.</p>\",\"PeriodicalId\":100403,\"journal\":{\"name\":\"Electron\",\"volume\":\"1 1\",\"pages\":\"\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2023-08-07\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://onlinelibrary.wiley.com/doi/epdf/10.1002/elt2.1\",\"citationCount\":\"1\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Electron\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1002/elt2.1\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Electron","FirstCategoryId":"1085","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/elt2.1","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 1
摘要
由于厚度较小,商业聚烯烃隔膜具有较低的孔隙率,以确保足够的热机械性能,从而导致曲折和扩大的Li+扩散路径,从而导致大的过电位和有害的枝晶生长。作为一种困境,高度多孔隔膜的探索因其大厚度而受到挑战,削弱了此类追求的适用性。本文设计了一种超多孔结构,通过将电解质亲和性聚(偏二氟乙烯-共-六氟丙烯)浸渍到超轻-3μm的3D聚四氟乙烯支架(缩写为UP3D)中来缩短Li+转移途径。孔隙率为74%的UP3D隔膜使Li+转移增强了70%,Li+转移电阻降低了77%(2.67 mΩmm−1),从而实现了22.7 mA cm−2的超高Li+通量,有效地缓解了隔膜上的Li+浓度梯度。使用隔膜,LiFePO4半电池在2 C下1000次循环后可提供118 mAh g−1的容量,无与伦比的容量保持率为90%,石墨|| LiNi0.6Co0.2Mn0.2O2袋状全电池在8.848 mA(1.4 mA cm−2)下可提供6.8 mWh cm−2的面能密度,阴极负载高达134.9 mg,该隔膜的可扩展生产反映了其在需要超高孔隙率和可靠性的隔膜的高通量电池应用中的良好潜力。
With small thickness, commercial polyolefin separators own low porosity to ensure sufficient thermomechanical properties, resulting in tortuous and enlarged Li+ diffusion pathways that induce large overpotentials and detrimental dendrite growth. As a dilemma, the exploration of highly porous separators has been challenged by their large thickness, impairing the applicability of such pursuits. Herein, an ultraporous architecture is designed to shorten Li+ transfer pathways by impregnating electrolyte-affinitive poly (vinylidene fluoride-co-hexafluoropropylene) into ultralight ∼3 μm 3D-polytetrafluoroethylene scaffold (abbreviated as UP3D). The UP3D separator with a porosity of 74% gives rise to 70% enhancement in Li+ transference and 77% reduction in Li+ transfer resistance (2.67 mΩ mm−1) and thus enables an ultrahigh Li+ flux of 22.7 mA cm−2, effectively alleviating Li+ concentration gradient across the separator. With the separator, the LiFePO4 half cell delivers a capacity of 118 mAh g−1 with an unparalleled capacity retention of 90% after 1000 cycles at 2 C, and a graphite || LiNi0.6Co0.2Mn0.2O2 pouch full cell delivers an areal energy density of 6.8 mWh cm−2 at 8.848 mA (1.4 mA cm−2) with a high cathode loading of 134.9 mg. Such results, together with the scalable production of the separator, reflect its promising potential in high-flux battery applications of separators that require both ultrahigh porosity and reliability.