Li-ion capacitors with carbon cathode and hard carbon/stabilized lithium metal powder anode electrodes

Cao, Weicheng; Zheng, Jim P.

doi:10.1016/j.jpowsour.2012.04.033

Cited by 225 publications

(187 citation statements)

References 14 publications

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“…All techniques and methods described above can be applied for the pre-lithiation of LICs, such as the electrochemical pre-lithiation [54,157,160,161], the pre-lithiation with additives inside the negative or positive electrode [162][163][164] or the pre-lithiation through direct contact with Li metal [165,166]. In contrast to pre-lithiation of LIBs, pre-lithiated LICs are already commercially available as described in the followings section.…”

Section: Pre-lithiation In Lithium-ion Capacitorsmentioning

confidence: 99%

Pre-Lithiation Strategies for Rechargeable Energy Storage Technologies: Concepts, Promises and Challenges

et al. 2018

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Abstract:In order to meet the sophisticated demands for large-scale applications such as electro-mobility, next generation energy storage technologies require advanced electrode active materials with enhanced gravimetric and volumetric capacities to achieve increased gravimetric energy and volumetric energy densities. However, most of these materials suffer from high 1st cycle active lithium losses, e.g., caused by solid electrolyte interphase (SEI) formation, which in turn hinder their broad commercial use so far. In general, the loss of active lithium permanently decreases the available energy by the consumption of lithium from the positive electrode material. Pre-lithiation is considered as a highly appealing technique to compensate for active lithium losses and, therefore, to increase the practical energy density. Various pre-lithiation techniques have been evaluated so far, including electrochemical and chemical pre-lithiation, pre-lithiation with the help of additives or the pre-lithiation by direct contact to lithium metal. In this review article, we will give a comprehensive overview about the various concepts for pre lithiation and controversially discuss their advantages and challenges. Furthermore, we will critically discuss possible effects on the cell performance and stability and assess the techniques with regard to their possible commercial exploration.

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Section: Pre-lithiation In Lithium-ion Capacitorsmentioning

confidence: 99%

Pre-Lithiation Strategies for Rechargeable Energy Storage Technologies: Concepts, Promises and Challenges

et al. 2018

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“…Apart from mitigating the initial cycle loss, pre-lithiation also improves the working potential of the device by providing a lower redox potential to the carbon anode, hence raising the overall cell potential, which further results into higher cell energy density, cycle stability and reduced electrode resistance. 2,6 Moreover, due to the pre-lithiation process, the anion-cation concentration in the electrolyte remains mostly stable during cycling, hence maintaining a steady electrolyte conductivity, which is crucial for cell efficiency and cyclability.Pre-lithiation can be achieved through several methods, 7 including electrochemically driven lithiation, 8 lithiation using external short, lithiation by use of a back-side sacrificial Li, lithiation through composite cathode, 9 lithiation from highly concentrated electrolyte 10 or by * Electrochemical Society Student Member. * * Electrochemical Society Member.…”

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confidence: 99%

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confidence: 99%

“…2,11 This latter method of direct-contact, also known as 'internal short circuit method', is a simple, controllable and an efficient way of lithiation since it doesn't require any re-arrangement or any special structural needs for the electrodes, hence reducing soaking and device assembly times and manufacturing costs. 12,13 The maximum amount of Li employed for doping cannot exceed the capacity of the negative electrode, otherwise the unused Li left over on the surface of the negative electrode after the completion of the pre-lithiation process, will affect the life and safety of the energy storage device due to the growth of the Li dendrites.…”

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confidence: 99%

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Investigation of Pre-lithiation in Graphite and Hard-Carbon Anodes Using Different Lithium Source Structures

Shellikeri

Watson

Adams

et al. 2017

J. Electrochem. Soc.

118

113

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Energy storage devices like batteries and supercapacitors, have become indispensable in portable devices and electric vehicles. But, the carbon anodes used in these devices, exhibit a significant loss in their initial capacity (graphite: 6.6% and hard carbon: 29.8%) due to the consumption of Li ions from electrolyte during solid electrolyte interface layer formation and other non-reversible reactions, and if unaddressed, can potentially diminish this advantage. Pre-lithiation treatment of carbon anodes can mitigate this loss, apart from improving the cell working potential, hence enhancing cell energy density and cyclability. We investigate in this report a direct-contact lithiation process in graphite and hard carbon anodes using four distinct lithium source structures. The results show that the type of Li-source structure employed for anode pre-lithiation can have a major impact on the electrode physical properties, pre-lithiation times and the pre-lithiation anode potentials achieved, potentially effecting the SEI properties, cycle life, and the electrode processing costs. for their reversible characteristic, where a guest ion (e.g. Li-ion) can be reversibly intercalated and de-intercalated into the host carbon material. On the other hand, the host carbon anode materials when in contact with organic electrolytes (Li salt in organic solvents), form an electronically passivating solid electrolyte interface (SEI) layer 3 on their surface by the reduction of electrolyte. This ensures the longterm stability of the device by passivating the carbon anode surface by preventing further reduction of the electrolyte on the anode surface. This SEI layer is ionically conductive enough to provide Li-ion pathways passing through it for further intercalation into the bulk of anode after de-solvating them, therefore preventing the co-intercalation of solvent molecules into the carbon structure. Although, the formation of SEI layer is necessary and beneficial, nevertheless, it consumes the Li-ions from the electrolyte, depleting it of charge carriers. This is the initial irreversible cycle loss 4 and if not compensated for, then it can drastically affect the efficiency and cyclability of the energy storage device. 5 The initial cycle loss can be mitigated by supplying additional Li-ions from Li reservoirs and this process is generally known as pre-lithiation. Apart from mitigating the initial cycle loss, pre-lithiation also improves the working potential of the device by providing a lower redox potential to the carbon anode, hence raising the overall cell potential, which further results into higher cell energy density, cycle stability and reduced electrode resistance. 2,6 Moreover, due to the pre-lithiation process, the anion-cation concentration in the electrolyte remains mostly stable during cycling, hence maintaining a steady electrolyte conductivity, which is crucial for cell efficiency and cyclability.Pre-lithiation can be achieved through several methods, 7 including electrochemically driven lithiation, 8 lithiation usi...

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“…13 A proper combination of such asymmetric electrode processes enables higher capacitance and operation voltage than those of conventional electric double-layer capacitors (EDLCs) and higher rate-capability than lithium-ion batteries (LIBs). 3,4 Up to the present, almost the same composition as the electrolyte of common LIBs has been utilized as the electrolyte of LIC. That is, a mixed alkylcarbonate solution dissolving lithium salt, like LiPF 6 /EC+DMC (EC: ethylene carbonate, DMC: dimethyl carbonate), is used, but its composition has not yet been optimized for LICs.…”

Section: Introductionmentioning

confidence: 99%

Ionic Conductivity of Nonflammable Ternary Electrolyte Consisting of Ionic Liquid and Fluorinated Alkylphosphate for Advanced Electrochemical Capacitors

et al. 2013

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A novel ternary electrolyte system that consists of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide (EMITFSA), LiTFSA, and tris(trifluoroethyl)phosphate (TFEP) has been developed as a nonflammable electrolyte for advanced electrochemical capacitors. The ionic conductivity of the system depended much on the electrolyte composition. Higher contents of EMITFSA gave higher conductivity in both binary EMITFSA-TFEP and ternary EMITFSA-LiTFSA-TFEP systems, whereas higher molar ratio of LiTFSA decreased the conductivity of the ternary system due to increased viscosity. In the systems keeping constant molar ratios of EMITFSA and LiTFSA, the conductivity showed maxima at ca. 70 mol% of TFEP, where the concentration of the charge carriers (ions) and the mobility of the species are balanced. Brief tests of a symmetric cell composed of activated carbon electrodes revealed that the present ternary component system work as a nonflammable electrolyte in carbon-based electrochemical capacitors.

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Li-ion capacitors with carbon cathode and hard carbon/stabilized lithium metal powder anode electrodes

Cited by 225 publications

References 14 publications

Pre-Lithiation Strategies for Rechargeable Energy Storage Technologies: Concepts, Promises and Challenges

Pre-Lithiation Strategies for Rechargeable Energy Storage Technologies: Concepts, Promises and Challenges

Investigation of Pre-lithiation in Graphite and Hard-Carbon Anodes Using Different Lithium Source Structures

Ionic Conductivity of Nonflammable Ternary Electrolyte Consisting of Ionic Liquid and Fluorinated Alkylphosphate for Advanced Electrochemical Capacitors

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