ACS Applied Energy Materials
·
2021
·
IF 6.024
Jun Ban,Xingxing Jiao,Yangyang Feng,Jing Xue,Cheng He,Jiangxuan Song
Lithium/fluorinated carbon (Li/CFx) batteries have received widespread attention due to their high specific energy density. However, the development of Li/CFx primary batteries is seriously hampered owing to the low electrical conductivity and poor wettability against the fluorinated carbon electrolyte. Here, we report a CFx-compatible fluorinated ether-containing electrolyte for all-temperature high-energy-density Li/CFx primary batteries. Specifically, a CFx-philic 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE) is introduced to the carbonate-based electrolyte as a cosolvent. Benefiting from the low viscosity and low freezing point of TTE, the conductivity and wettability are drastically improved, contributing to a lowered charge-transfer resistance. Thus, the modified electrolyte with TTE endows Li/CFx batteries with high energy density of 850 Wh kg–1 at 25 °C and 745 Wh kg–1 at 55 °C under the current density of 5000 mA g–1, accompanied by high power density of 9931 and 10046 W kg–1, respectively. Even at the freezing temperature of −50 °C, Li/CFx batteries can still exhibit a high middle value of voltage of 1.91 V, and the discharge capacity is 299 mAh g–1 at 100 mA g–1. The improvement of electrochemical performance over a wide temperature range from −50 to 55 °C has greatly expanded the application of Li/CFx batteries.
研究领域:
材料科学
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电化学
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能源存储
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DOI
高影响因子
Small
·
2022
·Vol. 18
·期 52
·2205017
·
IF 15.153
Xirui Kong,Yichen Kong,Yayun Zheng,Lang He,Du Wang,Yan Zhao
With a high energy density, lithium–sulfur batteries (LSB) are regarded as one of the promising next-generation energy storage systems. However, many challenges hinder the practical applications of LSB, such as the dendrite formations/parasitic reactions on the Li metal anode and the “shuttle effect” of lithium polysulfides of the LSB cathode. Herein, a novel diluted medium-concentrated electrolyte (DMCE) is developed by adding 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether (TTE) into a dual salt medium-concentrated electrolyte (MCE) consisting of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI)–lithium bis(fluorosulfonyl)imide (LiFSI)/tetrahydrofuran (THF)–dipropyl ether (DPE). The optimized DMCE electrolyte is capable of protecting the Li metal anode and suppresses the dissolution of polysulfides and the “shuttle effect”, delivering a high coulombic efficiency (CE) of Li plating–stripping up to 99.6% even at a low concentration of Li salt (1.0–2.0 m ). Impressively, compared with the cells cycled in the MCE electrolyte, the Li S cells with the DMCE-2.0 m electrolyte have delivered an enhanced initial capacity of 682 mAh g −1 with an excellent capacity retention of 92% for 500 cycles. This strategy of using fluorinated ether as diluent solvent in a medium-concentrated electrolyte can accelerate the commercialization of LSB.
研究领域:
材料科学
·
电化学
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产品关联
DOI
PubMed
高影响因子
FIRE TECHNOLOGY
·
2019
·Vol. 56
·期 6
·2349-2364
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IF 1.42
Zheng Hao,Fang Wei,Sun Yi,Liang Xin,Xiang Hongfa,Jiang Lihua,Wang Qingsong
Nonflammable electrolytes are promising substitutes for the state-of-the-art carbonate-based electrolytes in order to directly enhance the safety characteristics of lithium ion batteries. Combination of trimethyl phosphate (TMP) and a fluorinated ether of 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether (FEPE) is designed to formulate nonflammable electrolytes. The reformulated electrolytes of 1 mol/L LiPF 6 /TMP + FEPE (9:1, 8:2 and 7:3, w/w) are totally nonflammable. The FEPE solvent has higher oxidative stability and the FEPE-containing electrolytes have better separator wettability than the pure TMP electrolyte (1 mol/L LiPF 6 /TMP). The improved oxidative stability and separator wettability can enhance electrochemical stability of electrolyte on high-voltage cathode LiNi 0.5 Mn 1.5 O 4 . In Li 4 Ti 5 O 12 /LiNi 0.5 Mn 1.5 O 4 cells, the FEPE-containing electrolyte exhibits the better cycling stability than the pure TMP electrolyte, and the solvent composed of TMP + FEPE (8:2) is the optimal ratio. The Li 4 Ti 5 O 12 /LiNi 0.5 Mn 1.5 O 4 cell with the optimal electrolyte exhibits better rate capability because of the reduced polarization and improved oxidation stability. This work reveals the effect of fluorinated ethers on separator wettability of TMP-based nonflammable electrolytes and high-voltage applications.
研究领域:
材料科学
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电化学
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DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2019
·Vol. 166
·期 8
·A1456
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IF 3.12
Hao Zheng,Xin Zhou,Sheng Cheng,Ru Xia,Shuping Nie,Xin Liang,Yi Sun,Hongfa Xiang
Influence of separator wettability toward nonaqueous electrolyte was investigated in lithium-ion batteries using high-voltage LiNi0.5Mn1.5O4 cathode. A fluorinated ether of 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether (HFE) was introduced as a co-solvent into the control electrolyte and polyolefin separator wettability toward nonaqueous electrolyte was effectively enhanced. Even though conductivity of the electrolyte bulk decreased after HFE was introduced, ionic conductivity of the electrolyte-soaking separator increased due to the enhanced separator wettability. From cycling stability of the half cells using high-voltage LiNi0.5Mn1.5O4 cathode, all electrolytes containing 10%, 20% and 30% HFE have superiority to the control electrolyte, and the 20% HFE containing electrolyte is the optimal. Microscopical analysis revealed that oxidative decomposition of HFE-containing electrolyte on the LiNi0.5Mn1.5O4 cathode was suppressed effectively with the thinner cathode electrolyte interface than that in the control electrolyte. In Li4Ti5O12|LiNi0.5Mn1.5O4 full cells, the 20% HFE containing electrolyte exhibited the enhanced cycling stability and rate capability compared to the control of 1 mol L−1 LiPF6/propylene carbonate. This work here reveals the effect of fluorinated ether co-solvent on separator wettability and further the superior separator wettability is critical to the oxidation stability of the electrolyte in lithium-ion batteries using high-voltage cathode.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Nano Energy
·
2022
·
IF 19.069
Guangzhao Zhang,Xiaolan Deng,Jiawei Li,Jun Wang,Guoli Shi,Yu Yang,Jian Chang,Kai Yu,Shang-Sen Chi,Hui Wang,Peng Wang,Zhongbo Liu,Yuan Gao,Zijian Zheng,Yonghong Deng,Chaoyang Wang
The employment of localized high concentration electrolytes (LHCEs) has been demonstrated as an effective strategy for the fabrication of next-generation high-energy-density lithium metal batteries . However, the low ionic conductivity of LHCEs and their parasitic side reactions with lithium metal anodes severely hinder the cycling stability of lithium metal batteries. Herein, a partially fluorinated ether of bis (2,2-difluoroethyl) ether (BDE) is proposed as a bifunctional co-solvent to form novel LHCEs for realizing dendrite-free and long-term lithium metal batteries. The BDE co-solvent serves as a diluent to improve the ionic conductivity up to 6.4 mS/cm by dissociating lithium salt via weak interaction and decreasing the electrolyte viscosity. In addition, the BDE co-solvent could promote the formation of uniform lithium fluoride (LiF)-rich solid electrolyte interphase (SEI) to suppress the dendrite deposition by regulating the solvation shell structure , resulting in high Coulombic efficiency of 99.6%. As a result, the assembled full cell exhibits outstanding cycling stability (97% capacity retention after 200 cycles @0.5 C) with high areal capacity (2 mAh/cm 2 ) and high rate capability (2 C) under practical conditions (50 µm Li, lean electrolyte: 3 g/Ah). We also demonstrate the real application of electrolyte with a commercial cathode in 320-mAh-level pouch 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
Journal of Energy Chemistry
·
2023
·
IF 13.1
Ruo Wang,Jiawei Li,Bing Han,Qingrong Wang,Ruohong Ke,Tong Zhang,Xiaohu Ao,Guangzhao Zhang,Zhongbo Liu,Yunxian Qian,Fangfang Pan,Iseult Lynch,Jun Wang,Yonghong Deng
Li metal batteries using high-voltage layered oxides cathodes are of particular interest due to their high energy density. However, they suffer from short lifespan and extreme safety concerns, which are attributed to the degradation of layered oxides and the decomposition of electrolyte at high voltage, as well as the high reactivity of metallic Li. The key is the development of stable electrolytes against both high-voltage cathodes and Li with the formation of robust interphase films on the surfaces. Herein, we report a highly fluorinated ether, 1,1,1-trifluoro-2-[(2,2,2-trifluoroethoxy) methoxy] ethane (TTME), as a co-solvent, which not only functions as a diluent forming a localized high concentration electrolyte (LHCE), but also participates in the construction of the inner solvation structure. The TTME-based electrolyte is stable itself at high voltage and induces the formation of a unique double-layer solid electrolyte interphase (SEI) film, which is embodied as one layer rich in crystalline structural components for enhanced mechanical strength and another amorphous layer with a higher concentration of organic components for enhanced flexibility. The Li||Cu cells display a noticeably high Coulombic efficiency of 99.28% after 300 cycles and Li symmetric cells maintain stable cycling more than 3200 h at 0.5 mA/cm 2 and 1.0 mAh/cm 2 . In addition, lithium metal cells using LiNi 0.8 Co 0.1 Mn 0.1 O 2 and LiCoO 2 cathodes (both loadings ∼3.0 mAh/cm 2 ) realize capacity retentions of >85% over 240 cycles with a charge cut-off voltage of 4.4 V and 90% for 170 cycles with a charge cut-off voltage of 4.5 V, respectively. This study offers a bifunctional ether-based electrolyte solvent beneficial for high-voltage Li metal batteries.
研究领域:
材料科学
·
电化学
·
能源存储技术
✓ 已验证
产品关联
DOI
高影响因子
ACS Nano
·
2025
·
IF 16
Chenyang Jiao,Qizheng Zheng,Kang Zhang,Jiyuan Xue,Na Liu,Baodan Zhang,Yueli Lin,Xuequan Zhu,Changhao Wang,Hong-Gang Liao,Chong-Heng Shen,Yeguo Zou,Yu Qiao,Shi-Gang Sun
High-energy-density Li-rich layered oxide-based Li-metal batteries depend critically on the unique anionic redox. However, severe electrolyte decomposition and interfacial structural degradation hinder the longevity and stability of Li-rich||Li-metal batteries. Here, we show that a rational hybrid electrolyte design strategy can regulate interfacial chemistry through precise manipulation of cathode surface-exposed nucleophilic species. As a proof of concept, ethyl methyl sulfone is employed as the primary solvent due to its oxidative stability and resistance to nucleophilic attack, simultaneously strategically fabricating a fluorinated ether as a cosolvent that directs nucleophilic reaction toward its targeted functionality. Furthermore, this hybrid electrolyte design simultaneously facilitates the formation of a LiF-rich cathode electrolyte interphase (CEI) and reorganizes the solid electrolyte interphase on the Li metal from the preferential decomposition of cosolvents and anions. As a result, ultrahigh Coulombic efficiency (CE) (>99.4%) for Li-rich cathodes and enhanced Li-metal plating/stripping reversibility are achieved. Consequently, the optimized electrolyte demonstrates exceptional cycling stability, retaining 92% capacity over 100 cycles with ultrahigh average CE (>99.3%) under demanding conditions (limited Li supply, N/P = 2). Remarkably, this hybrid electrolyte enabled superior operation with anode-free cell architectures and enabled extreme temperatures (−30 to 55 °C) cycling. By effectively transforming detrimental nucleophilic attack into interfacial enhancement, this work establishes a new paradigm for electrolyte design in utilizing anionic redox chemistry.
研究领域:
电化学
·
能源材料
·
固态离子学
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电池技术
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界面科学
·
材料化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Chem
·
2022
·
IF 25.832
Zunchun Wu,Ruhong Li,Shuoqing Zhang,Ling lv,Tao Deng,Hao Zhang,Ruixin Zhang,Jiangjiang Liu,Shouhong Ding,Liwu Fan,Lixin Chen,Xiulin Fan
The stability of localized high-concentrated electrolytes (LHCEs) on the Li metal anode has been well established, but the understanding of its oxidation chemistry for high-voltage cathodes is unclear. Here, we demonstrate that the de-coordination between Li + and solvents defines the anodic stability of LHCEs, which can be finely tuned by the ambient diluents. After screening the possible diluents, we found that 2H,3H-decafluoropentane (HFC) satisfies the principle of relatively weak but sufficient interactions with solvation shell, thus strengthening the Li + coordination and offering electrolytes excellent antioxidant chemistry. The proposed HFC-LHCE enables practical Li metal batteries to realize >90% capacity retention with a Coulombic efficiency of 99.91% for >180 cycles under aggressive conditions (4.4 V 20-μm-Li||3.7-mAh cm −2 -LiNi 0.8 Mn 0.1 Co 0.1 O 2 and 4.5 V 20-μm-Li||4-mAh cm −2 -LiCoO 2 cells). This work presents guiding principles for improving electrolyte cathodic and anodic stability, which benefits the development of LHCEs and inspires the formulation of next-generation lithium batteries.
研究领域:
电化学
·
能源材料
·
锂离子电池
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界面化学
·
电解质工程
·
储能技术
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Haifeng Tu,Linge Li,Yuzhen Hu,Yongyi Zhang,Yongjiang Wang,Wei Huang,Zhiqiang Ren,Hongzhen Lin,Meinan Liu
Lithium-metal batterie (LMB) is regarded as one the most promising high energy battery systems, however the safety concern from lithium dendrites and organic liquid electrolytes seriously impedes its widely application. Herein, a non-flammable liquid “polymer-in-salt” composite electrolyte with superior dendrite-suppression capability is well designed and achieved by using lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt, polyethylene glycol dimethyl ether (PEGDME) and 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropylether (TTE). Non-flammable TTE used here is on one hand to reduce the high viscosity of this “PEGDME polymer in LiTFSI salt” electrolyte (PISE), and thus enhance its wettability; on the other hand, to maintain the merits of highly contented salt. By taking advantage of these localized highly concentrated lithium salts, aggregated ion clusters are generated in this PISE-TTE system, which construct fast ionic transportation channels, and thus accelerates Li + transportation. Furthermore, this PISE-TTE electrolyte system interacts with Li anode forming a robust organic/inorganic dual layer solid electrolyte interphase (SEI) layer. With the assistance of this tough SEI, the optimized PISE 0.7 -TTE 90 exhibits outstanding anti-dendrite growth behavior in Li/Li and Li/Cu cells. Moreover, PISE 0.7 -TTE 90 also delivers an impressive performance in both Li/LiFePO 4 (LFP, a capacity of 150 mAh g −1 at 0.5C after 150 cycles) and Li@Cu/LFP (electrochemically deposited Li on Cu current collector, a capacity of 150 mAh g −1 at 0.5C after 50 cycles) cells.
研究领域:
电化学
·
能源材料
·
电池技术
·
纳米材料
·
界面化学
·
高分子科学
·
电化学储能
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）