甲基膦酸二甲酯改性的不易燃PVDF基凝胶聚合物电解质用于宽温域、长循环寿命和高安全性锂金属电池
Nonflammable PVDF-based gel polymer electrolytes modified by dimethyl methylphosphate for wide temperature range,long cycle-life and high-safety lithium metal batteries
赵媛君 1答欣宇 1秦棪阳 1贾鑫 1邓雪甜 1丁书江 1熊俊俏 2荣强 2孔祥鹏 2高国新1
作者信息
- 1. Xi'an Key Laboratory of Sustainable Energy Materials Chemistry,School of Chemistry,Xi'an Jiaotong University,Xi'an 710049,China
- 2. Hunan Desay Battery Co.Ltd.,Changsha 410203,China
- 折叠
摘要
凝胶聚合物电解质(GPEs)被认为是开发具有高能量密度和高安全性的锂金属电池(LMBs)的有希望的候选材料,然而大多数报道的GPEs是易燃的,使得LMBs仍然面临巨大的安全风险.在这里,我们使用甲基膦酸二甲酯(DMMP)作为功能性阻燃剂和增塑剂,用于聚偏二氟乙烯(PVDF)基质,开发了一种新型的不易燃PVDF-DMMP GPEs用于LMBs.这种DMMP不仅极大地增强了PVDF-DMMP GPEs的阻燃性,还有效提高了锂盐的解离效率和锂离子的快速传输,同时还有助于形成稳定且坚固的CEI/SEI层.因此,超薄的PVDF-DMMP GPEs(约20微米)展现出卓越的阻燃性、高离子导电性(在30℃下为1.34×10-3 S cm-1)、快速的锂离子迁移(在30℃下tLi.=0.59)、在30-80℃下具有宽的电化学稳定性电压窗口(超过4 V)以及均匀的锂沉积.当用于Li||Li对称电池、Li||LiFePO4(LFP)和Li||LiNi0.8Co0.1Mn0.1O2全电池时,不易燃的PVDF-DMMP GPEs能够使这些电池同时具有长期循环稳定性、高倍率性能、宽温度工作范围(从-20到80℃)和高安全性.即使在遭受严苛的破坏性测试时,Li|PVDF-DMMP GPEs|LFP软包电池仍然正常工作,没有任何安全风险.实际的软包电池能量密度高达508 Wh kg-1.因此,我们的工作可以为设计高安全性和高能量密度的LMBs提供新的策略.
Abstract
Gel polymer electrolytes(GPEs)has been con-sidered as a promising candidate for the development of li-thium metal batteries(LMBs)with high energy density and high safety,yet most reported GPEs is flammable,making the LMBs still facing great safety hazards.Herein,we used di-methyl methylphosphate(DMMP)as the functional flame retardant and plasticizer for poly(vinylidene fluoride)(PVDF)matrix to develop a novel nonflammable PVDF-DMMP GPEs for LMBs.The DMMP not only highly enhances the flame resistance of PVDF-DMMP GPEs,the efficient dissociation of lithium salt and the rapid transport of lithium ions,but also helps to form stable and robust CEI/SEI layers.As a result,the ultrathin PVDF-DMMP GPEs(～20 μm)present superb flame resistance,high ionic conductivity(1.34 × 10-3 S cm-1 at 30℃),fast lithium ion transport(tu+=0.59 at 30℃),high electrochemical stability voltage window(over 4 V)at 30-80℃ and uniform lithium deposition.When used in Li||Li sym-metric cells,Li||LiFePO4(LFP)and Li||LiNi0.8Co0.1Mn0.1O2 full cells,the nonflammable PVDF-DMMP GPEs could endow these cells with long-term cycle stability,high rate capability,wide-temperature operation ranges(from-20 to 80℃)and high safety simultaneously.Even when suffering from harsh deconstructive tests,the Li|PVDF-DMMP GPEs|LFP pouch cells still work normally without any safety hazards.The actual energy density of the packed pouch cell is as high as 508 Wh kg-1.Therefore,our work can provide a promising strategy for the design of high safety and high-energy-density LMBs.
关键词
lithium metal batteries/gel polymer electrolyte/flame resistance/PVDFKey words
lithium metal batteries/gel polymer electrolyte/flame resistance/PVDF引用本文复制引用
出版年
2024
NETL
NSTL
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