JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2021
·Vol. 168
·期 12
·120548
·
IF 4.316
Mingwei Shi,Zailei Zhang,Man Zhao,Xianmao Lu,Zhong Lin Wang
For supercapacitors, high self-discharge rate is an inevitable issue that causes fast decay of cell voltage and loss of stored energy. Designing supercapacitors with suppressed self-discharge for long-term energy storage has been a challenge. In this work, we demonstrate that substantially reduced self-discharge rate can be achieved by using highly concentrated electrolytes. Specifically, when supercapacitors with 14 M LiCl electrolyte are charged to 0.80 V, the open circuit voltage (OCV) drops to 0.65 V in 24 h. In stark contrast, when the electrolyte concentration is reduced to 1 M, the OCV drops from 0.80 to 0.65 V within only 0.3 h, which was 80 times faster than that with 14 M LiCl. Decreased OCV decay rate at high electrolyte concentration is also confirmed for supercapacitors with different electrolytes (e.g., LiNO3) or at higher charging voltages (1.60 V). The slow self-discharge in highly concentrated electrolyte can be largely attributed to impeded electron transfer between the electrodes and electrolyte due to the formation of hydration clusters and reduced amount of free water molecules, thereby faradaic reactions that cause fast self-discharge are reduced. Our study not only supports the newly revised model about the formation of electric double layer with the inclusion of electron transfer, but also points a direction for substantially reducing the self-discharge rate of supercapacitors.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
IONICS
·
2023
·Vol. 29
·期 4
·1381-1393
·
IF 2.8
Zeng Yong,Wang Keliang,Ke Xiang,Tan Xiaoqing,Jiang Bo,Zhu Weichen,Xiao Rengui
Compared with Li-ion batteries, dual-graphite batteries (DGBs) have low cost, easy handling, and renewable advantages. However, DGBs with pure ionic liquid as the electrolyte (LEDGBs) suffer from high self-discharge rate (SDR). Here, a gel polymer electrolyte (ILGPE) was prepared using polyvinylidene fluoride as the polymer matrix and 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide as the electrolyte and assembled into a gel polymer double-graphite battery (IGDGB). The results show that the IGDGB has an initial discharge capacity of 34.9 mAh g -1 , and SDR is only 3.63%/h lower than the LEDGB (25.07%/h) after resting for 3 h. Notably, even after resting for 10 h, the IGDGB still has a discharge capacity of 27.5 mAh g -1 . Meanwhile, the electrochemical impedance spectroscopy analysis results indicate that the low SDR of IGDGB is due to the limiting effect of ILGPE on the carrier strength. This result provides an idea of self-discharge reduction strategy for other electrochemical energy storage systems with intercalation storage mechanism.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Shiqi Ding,Xin Dai,Zhenjiang Li,Alan Meng,Lei Wang,Guicun Li,Shaoxiang Li
VS 4 is one of the most potential cathode materials candidates for magnesium ion batteries (MIBs). However, it is still challenging for suitably modifying VS 4 to make it process more excellent cycle and rate performance. Herein, modifying VS 4 with cation (Mo)/anion (O) co-doping (MVSO) enhances the electrical conductivity, generates rich sulfur and oxygen vacancies, induces the co-existence of V 3+ /V 4+ and regulates the morphology as hollow flower-like morphology. Benefitted from the advantages of co-doping of Mo and O, MVSO delivers the excellent electrochemical properties, such as the high specific capacity (140.5 mAh g −1 ) under 50 mA g −1 , ultralong cycling life about 1000 cycles with capacity retention ratio of 95.6%, superior rate capability (the capacity could achieve at 75.2 mAh g −1 , when the current density increases to 1000 mA g −1 ), and low self-discharge ratio. Furthermore, the fast reaction kinetics and high capacitive process contribution for MVSO unmasked by the galvanostatic intermittent titration technique (GITT) and pesudocapaticance-like contribution analysis are highlighted. Particularly, the intrinsic Mg 2+ storage mechanism and the high reversible properties caused by Mo-O co-doping is unveiled with comprehensive ex situ characterizations. These findings are supposed to open new avenues for designing cathode materials for applying in future energy storage devices.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2025
·
IF 19
Yaxin Zhang,Tongshuai Wang,Jiawen Tang,Yunsong Li,Yuxiang Guo,Lu Cheng,Jiacheng Liu,Ahu Shao,Chunwei Li,Zhiqiao Wang,Xiaoyu Tang,Yisheng Hu,Yue Ma
The paradigm shift toward the disposal of retired batteries demands sustainable and cost-effective recycling methods that surpass conventional pyro-/hydrometallurgy-based techniques, offering superior profitability, energy efficiency, resource utilization, and environmental benefits. In this study, a one-step modulation approach is presented for regenerating spent Ni-rich layered oxides featured with exceptional ion diffusivity and high-temperature stability. By exploiting decomposed species from Li 6 Zr 2 O 7 , monitored via high-temperature X-ray diffraction, the strategy simultaneously enables: Li source replenishment, Zr doping into the bulk lattice, and Conformal ion-conductive Li 2 ZrO 3 coating on regenerated LiNi 0.8 Co 0.1 Mn 0.1 O 2 (R-NCM811-2%LZO). Crucially, the upcycling process strategically utilizes lattice vacancies in the oxide to facilitate Zr dopant diffusion, while Li 2 ZrO 3 coating elevates corrosion resistance and thermal stability. Operando phase tracking reveals that the regenerated cathode maintains reversible lattice breathing and undergoes a continuous, kinetics-boosted phase transition. By pairing R-NCM811-2%LZO cathode with graphite anode in a 3.0 Ah pouch-format cell, the prototype achieves an energy density of 302 Wh kg −1 , extreme power output of 1260 W kg −1 , 63% mitigation of self-discharge rate at 55 °C, as well as robust cycling across a wide temperature range. This value-added strategy upgrades spent NCM811 into high-temperature-tolerant, fast-charging cathodes, paving the way for sustainable battery recycling and circular economy initiatives.
研究领域:
材料科学
·
电化学
·
储能技术
·
电池回收
·
纳米技术
·
环境科学
·
固态化学
✓ 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）