Frontiers in Chemistry
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2019
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IF 3.782
Yu Juan,Gao Na,Peng Jiaxin,Ma Nani,Liu Xiaoyan,Shen Chao,Xie Keyu,Fang Zhao
Nowadays, lithium (Li) metal batteries arouse widespread concerns due to its ultrahigh specific capacity (3,860 mAh g−1). However, the growth of Li dendrites has always limited their industrial development. In this paper, the use of concentrated electrolyte with lithium difluoro(oxalate)borate (LiODFB) salt in 1, 2-dimethoxyethane (DME) enables the good cycling of a Li metal anode at high Coulombic efficiency (up to 98.1%) without dendrite growth. Furthermore, a Li/Li cell can be cycled at 1 mA cm−2 for over 3,000 h. Besides, compared to conventional LiPF6-carbonate electrolyte, Li/LiFePO4 cells with 4 M LiODFB-DME exhibit superior electrochemical performances, especially at high temperature (65°C). These outstanding performances can be certified to the increased availability of Li+ concentration and the merits of LiODFB salt. We believe that the concentrated LiODFB electrolyte is help to enable practical applications for Li metal anode in rechargeable batteries.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Energy Materials
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2021
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IF 6.024
Shengdong Tao,Jian Li,Lihua Wang,Weiguo Huang,Minchao Zhang,Zhexi Chi,Shuohan Wang,Yongzhi Chen,Lei Shang
Development of an active filler with a large specific surface area, fast ion conductivity phase, special shape, and high electrochemical stability is a critical issue for prominent performance composite solid-state electrolytes (CSEs) in solid-state lithium-ion batteries. Here, we report large specific surface area and coral-like cubic Li7La3Zr2O12 (LLZO) that was synthesized via a metal–organic framework (MOF) at a low calcination temperature (1000 °C). As active fillers, the coral-like cubic LLZO and lithium oxalyldifluroborate (LiODFB) uniformly distributed in a poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) matrix provide an interconnected Li-ion transport channel in CSE, which manifests outstanding properties such as a favorable electrochemical stability window (of 4.85 V vs Li/Li+), high ionic conductivity (1.65 × 10–4 S cm–1, 20 °C), and superior interface compatibility with lithium metal. The assembled LiFePO4/CSE/Li and LiCoO2/CSE/Li cells convey predominate performance and initial specific capacities of 135.0 and 135.9 mA h g–1 at 0.5 C, with capacity retention values of 83.51% after 500 cycles and 93.90% after 200 cycles. The coral-like LLZO with a large specific area reduces polymer crystallinity and provides a large phase interface in CSE through interaction of LLZO with LiODFB and PVDF-HFP. The results suggest that coral-like LLZO prepared by MOFs is a promising filler in CSEs for solid-state lithium-ion batteries.
研究领域:
材料科学
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电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
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2017
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IF 3.012
Hongming Zhou,Demin Xiao,Chengjie Yin,Zhaohui Yang,Kaiwen Xiao,Jian Li
The electrolytes based on lithium difluoro(oxalate)borate (LiODFB) and sulfolane (SL) including LiODFB-ethylene carbonate (EC)/dimethyl carbonate (DMC) and LiPF 6 -EC/DMC as the references have been studied on electrochemical performance and interfacial stability in Li/LiNi 0.5 Mn 1.5 O 4 cells. LiODFB-containing electrolytes show outstanding electrochemical stability within 5.5 V due to the passivation phenomenon on the cathodes, while LiPF 6 -containing electrolytes undergo continuous decomposition beyond 4.5 V. The initial charge/discharge profiles and cyclic voltammetry (CV) curves prove that the cell with LiODFB-SL/DMC(2:1 by vol.) electrolyte has lower degree of polarization and better reversibility. The cathode with LiODFB-SL/DMC(2:1 by vol.) electrolyte displays the best cycling performance and the cathode with LiPF 6 -EC/DMC(1:1 by vol.) electrolyte displays the worst cycling performance. AC impedance shows that the cell cycling with LiODFB-SL/DMC(2:1 by vol.) electrolyte has much smaller resistance of charge transfer on cathode/electrolyte interface than the cell cycling with LiODFB-EC/DMC(1:1 by vol.) electrolyte. The characterization of the cathode surfaces indicates that a more homogeneous and compact passivation layer forms on the cathode cycling with LiODFB-SL/DMC(2:1 by vol.) electrolyte to greatly improve the interfacial stability for the reason that SL motivates the passivation reaction of LiODFB and itself participates the formation of the passivation layers. Therefore, LiODFB-SL/DMC(2:1 by vol.) is a promising electrolyte for LiNi 0.5 Mn 1.5 O 4 cathode.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2021
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IF 5.316
Hongxia Chen,Bin Liu,Ya Wang,Hao Guan,Hongming Zhou
Spinel LiNi 0.5 Mn 1.5 O 4 (LNMO) cathode with high voltage plateau at around 4.7 V (vs. Li/Li + ) has attracted great attention. However, the lack of suitable electrolyte hinders its application. Although lithium difluoro(oxalate)borate (LiODFB)-based electrolyte has been proved to be suitable for high voltage electrolyte, traditional LiODFB-based electrolyte has poor low and high temperature performance. Therefore, we confirm that lithium difluorophosphate (LiPO 2 F 2 , LiDFP) as LiODFB-based electrolyte additive and dimethyl sulfite (DMS) as co-solvent significantly improve electrochemical performance of LNMO/Graphite full batteries at low and high temperature. Various physical and electrochemical techniques are used to investigate the effect of four electrolytes. The effect on cathode is mainly attributed to priority oxidation decomposition of LiDFP. The formed interface film can inhibit the dissolution of Mn 2+ , thereby improving the high temperature electrochemical performance. The effect on anode is that the interface film formed by LiODFB prevents continuous reduction of solvents and additive. The enhanced low temperature performance is due to the significantly increased ionic conductivity of DMS-containing electrolytes at low temperature. Besides, the formed of the cathode electrolyte interphase (CEI) membrane with low impedance by LiDFP can improve the kinetics of cathode/electrolyte interface, therefore enhancing the low and high temperature performance of LNMO/Graphite full cells.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）