Highly concentrated electrolyte solutions for 4 V class potassium-ion batteries

Hosaka, Tomooki; Kubota, Kei; Kojima, Hiroki; Komaba, Shinichi

doi:10.1039/c8cc04433c

Cited by 200 publications

(270 citation statements)

References 25 publications

Supporting

Mentioning

241

Contrasting

Order By: Relevance

“…The KPF 6 is excluded due to its low solubility in DME, PC, and EC-DEC (1:1 by volume) solvent. [25]. Note that the KFSI/DME shows a higher ionic conductivity than KPF 6 /DME and KTFSI/DME at the same molality, which Adv.…”

mentioning

confidence: 90%

“…[21][22][23][24] In 2007, Jeong adopted the concentrated lithium bisperfluoroethylsulfonyl imide LiN(SO 2 C 2 F 5 ) 2 / propylene carbonate (PC) to realize a reversible graphite anode for lithium-ion batteries. [25,26] Despite these progresses, the issues of high viscosity, low ionic conductivity, and the increased cost of the HCE still hinder its practical applications. [25,26] Despite these progresses, the issues of high viscosity, low ionic conductivity, and the increased cost of the HCE still hinder its practical applications.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Localized High‐Concentration Electrolytes Boost Potassium Storage in High‐Loading Graphite

Qin

Xiao

Zheng

et al. 2019

Advanced Energy Materials

184

155

View full text Add to dashboard Cite

graphite has a theoretical capacity of 279 mAh g −1 . [3,17] In 2015, Ji and Hu have separately demonstrated the electrochemical intercalation of K ions into graphite in potassium hexafluorophosphate (KPF 6 )/ ethylene carbonate (EC)-diethyl carbonate (DEC) electrolytes. [4,18] However, their works did not achieve a highly reversible K + insertion/extraction process in KPF 6 /EC-DEC electrolyte because the formed solid electrolyte interphase (SEI) becomes fragile and unstable due to the large volume variation (≈60%) during K + insertion/extraction. [19,20] Compared to the conventional lowconcentration electrolyte (LCE), adopting a high-concentration electrolyte (HCE, e.g., >3 m) is a promising strategy to solve the above problem because it possesses some unusual physicochemical and electrochemical properties due to the unique solvation structure of ions, which make it different from an LCE. [21][22][23][24] In 2007, Jeong adopted the concentrated lithium bisperfluoroethylsulfonyl imide LiN(SO 2 C 2 F 5 ) 2 / propylene carbonate (PC) to realize a reversible graphite anode for lithium-ion batteries. [24] Recently, Komaba and Lu have reported the highly reversible graphite anode for PIBs at concentrated potassium bis(fluorosulfonyl)imide (KFSI)/ dimethoxyethane (DME) and KFSI/ethyl methyl carbonate electrolytes, respectively. [25,26] Despite these progresses, the issues of high viscosity, low ionic conductivity, and the increased cost of the HCE still hinder its practical applications. To overcome these disadvantages in using HCE, several groups have added a low-polarity cosolvent to dilute an HCE by forming a localized high-concentration electrolyte (LHCE). It is believed that the introduced cosolvent does not participate in the solvation process. Zhang's group used the bis(2,2,2,-tri-fluoroethyl) ether to dilute the concentrated lithium bis(fluorosulfonyl) imide (LiFSI)/dimethyl carbonate and improve the coulombic efficiency (CE) of lithium metal anodes without dendrite formation. [27] They also diluted concentrated LiFSI in sulfone with a fluorinated ether for high-voltage (4.9 V) lithium metal batteries. [28] Wang's group used the same cosolvent in the concentrated LiFSI/DME to increase both coulombic efficiencies of S cathode and Li anode for Li-S batteries. [29] However, none of the LHCE reported to date has been applied in PIBs, its stability and compatibility with PIBs remain in question.Herein, our work reports for the first time that a highly reversible K + insertion/extraction into graphite interlayer can Reversible intercalation of potassium-ion (K + ) into graphite makes it a promising anode material for rechargeable potassium-ion batteries (PIBs). However, the current graphite anodes in PIBs often suffer from poor cyclic stability with low coulombic efficiency. A stable solid electrolyte interphase (SEI) is necessary for stabilizing the large interlayer expansion during K + insertion. Herein, a localized high-concentration electrolyte (LHCE) is designed by adding a highly fluorinated ether into the con...

show abstract

mentioning

confidence: 90%

mentioning

confidence: 99%

Localized High‐Concentration Electrolytes Boost Potassium Storage in High‐Loading Graphite

Qin

Xiao

Zheng

et al. 2019

Advanced Energy Materials

184

155

View full text Add to dashboard Cite

show abstract

“…Since optimum electrolyte salts and solvents are crucial to realize maximum electrochemical properties of an electrode material, different electrolytes such as 1 m KPF 6 in EC:PC (1:1 v/v), 1 m KPF 6 in ethylene carbonate (EC):propylene carbonate (PC) (1:1 v/v) with 2 vol% fluoroethylene carbonate (FEC) and a highly concentrated electrolyte, 7 mol kg −1 KFSA in DME [25] were used for the electrochemical test. The cells were tested with composite electrodes containing active material, acetylene black and sodium polyacrylate binder in a weight ratio of 72:18:10 in the voltage window, 2.5-4.5 V versus K, at room temperature.…”

Section: Effect Of Electrolytementioning

confidence: 99%

“…[25] Since KPF 6 has limited solubility in organic solvents, a highly concentrated electrolyte was obtained by using potassium bis(fluorosulfonyl)amide (KFSA). [25] Since KPF 6 has limited solubility in organic solvents, a highly concentrated electrolyte was obtained by using potassium bis(fluorosulfonyl)amide (KFSA).…”

Section: Effect Of Electrolytementioning

confidence: 99%

“…[25] Since KPF 6 has limited solubility in organic solvents, a highly concentrated electrolyte was obtained by using potassium bis(fluorosulfonyl)amide (KFSA). [25] As shown in Table 1 and Figure 2a, high charge and discharge capacities of 112 and 98 mAh g −1 , respectively were observed for the G-KVPox electrode at the initial cycle. [25] As shown in Table 1 and Figure 2a, high charge and discharge capacities of 112 and 98 mAh g −1 , respectively were observed for the G-KVPox electrode at the initial cycle.…”

Section: Effect Of Electrolytementioning

confidence: 99%

See 1 more Smart Citation

A Layered Inorganic–Organic Open Framework Material as a 4 V Positive Electrode with High‐Rate Performance for K‐Ion Batteries

Hameed

Katogi

Kubota

et al. 2019

Advanced Energy Materials

Self Cite

View full text Add to dashboard Cite

K‐ion batteries (KIBs) are promising for large‐scale energy storage owing to various advantages like the high abundance of potassium resources in the Earth's crust, high operational potentials, and high power due to fast diffusion of K+ ions. However, to realize the practical application of KIBs, electrode materials are needed with high operational voltage, good capacity, long cycle life, and low‐cost. This work reports a layered open framework material, K2[(VOHPO4)2(C2O4)], composited with reduced graphene oxide (rGO) as a 4 V positive electrode material for KIBs. The material is prepared by a simple precipitation reaction at room temperature. The material demonstrates reversible K‐extraction/insertion with conventional carbonate ester KPF6 solutions; however, with low specific capacity and low Coulombic efficiency. A high discharge capacity of >100 mAh g−1 with good cycling stability and higher Coulombic efficiency is achieved in a highly concentrated electrolyte, 7 mol kg−1 of potassium bis(fluorosulfonyl)amide (KFSA) in dimethoxyethane (DME) at 0.1 C rate. Due to the facile migration of K+ ions in the framework, the material exhibits excellent rate capability with a discharge capacity of 80 mAh g−1 at 10 C rate, and a good capacity retention of 67% after 500 cycles at 2 C rate.

show abstract

Additives Engineered Nonflammable Electrolyte for Safer Potassium Ion Batteries

Liu

Cao

Zhou

et al. 2020

Adv Funct Materials

106

View full text Add to dashboard Cite

Potassium ion batteries (KIBs) are attracting great attention as an alternative to lithium-ion batteries due to lower cost and better global sustainability of potassium. However, designing electrolytes compatible with the graphite anode and addressing the safety issue of highly active potassium remains challenging. Herein, a new concept of using additives to engineer nonflammable electrolytes for safer KIBs is introduced. It is discovered that the additives, such as the ethylene sulfate (i.e., DTD), can make the electrolyte of 1.0 m potassium bis(fluorosulfonyl) imide in trimethyl phosphate compatible with graphite anode for the first time, without the need of concentrated electrolyte strategies. A new coordination mechanism of additives in the electrolyte is presented. It is shown that the additive can change the K + solvation structure and then determine the interfacial behaviors of K +-solvent on electrode interface, which are critical to affect the graphite performance (i.e., K +-solvent co-insertion, or K + (de-)intercalation). Then, an extremely high potassium storage capability is obtained in graphite electrode for potassium (ion) batteries, particularly the presented high-performance graphite|K 0.69 CrO 2 full battery fully demonstrates the practical application of this newly designed electrolyte. This additive-based strategy can offer more opportunities to tune the electrolyte properties and then serve for the more mobile ion battery system.

show abstract

Highly concentrated electrolyte solutions for 4 V class potassium-ion batteries

Cited by 200 publications

References 25 publications

Localized High‐Concentration Electrolytes Boost Potassium Storage in High‐Loading Graphite

Localized High‐Concentration Electrolytes Boost Potassium Storage in High‐Loading Graphite

A Layered Inorganic–Organic Open Framework Material as a 4 V Positive Electrode with High‐Rate Performance for K‐Ion Batteries

Additives Engineered Nonflammable Electrolyte for Safer Potassium Ion Batteries

Contact Info

Product

Resources

About