Oxocarbon Salts for Fast Rechargeable Batteries

Abstract

Oxocarbon salts (M2 (CO)n ) prepared through one-pot proton exchange reactions with different metal ions (M=Li, Na, K) and frameworks (n=4, 5, 6) have been rationally designed and used as electrodes in rechargeable Li, Na, and K-ion batteries. The results show that M2 (CO)5 /M2 (CO)6 salts can insert two or four metal ions reversibly, while M2 (CO)4 shows less electrochemical activity. Especially, we discover that the K2 C6 O6 electrode enables ultrafast potassium-ion insertion/extraction with 212 mA h g(-1) at 0.2 C and 164 mA h g(-1) at 10 C. This behavior can be ascribed to the natural semiconductor property of K2 C6 O6 with a narrow band gap close to 0.9 eV, the high ionic conductivity of the K-ion electrolyte, and the facilitated K-ion diffusion process. Moreover, a first example of a K-ion battery with a rocking-chair reaction mechanism of K2 C6 O6 as cathode and K4 C6 O6 as anode is introduced, displaying an operation voltage of 1.1 V and an energy density of 35 Wh kg(-1) . This work provides an interesting strategy for constructing rapid K-ion batteries with renewable and abundant potassium materials.

Molecular Engineering with Organic Carbonyl Electrode Materials for Advanced Stationary and Redox Flow Rechargeable Batteries

“…[194][195][196][197][198][199][200][201][202][203] For example, potassium ion batteries are potential sustainable battery systems for large-scale applications due to the abundance and low cost of potassium. [194][195][196][197][198][199][200][201][202][203] For example, potassium ion batteries are potential sustainable battery systems for large-scale applications due to the abundance and low cost of potassium.…”

Few‐Layered Tin Sulfide Nanosheets Supported on Reduced Graphene Oxide as a High‐Performance Anode for Potassium‐Ion Batteries

“…Recently, PIBs have been considered as promising alternatives to LIBs due to the abundant natural storage of potassium. Owing to much weaker Lewis acidity of K + ions, smaller solvated K + ions lead to higher ionic conductivity and larger transference number in electrolytes, as well as lower desolvation energy with regard to those of Li + and Na + . Furthermore, the redox standard hydrogen potential of K/K + (−2.92 V vs standard hydrogen electrode [SHE]) is lower than that of Na/Na + (−2.71 V vs SHE) and close to that of Li/Li + (−3.04 V vs SHE), leading to higher operating voltage and higher energy density for PIBs .…”

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weaker Lewis acidity of K + ions, smaller solvated K + ions lead to higher ionic conductivity and larger transference number in electrolytes, as well as lower desolvation energy with regard to those of Li + and Na + . [8,9] Furthermore, the redox standard hydrogen potential of K/K + (−2.92 V vs standard hydrogen electrode [SHE]) is lower than that of Na/Na + (−2.71 V vs SHE) and close to that of Li/Li + (−3.04 V vs SHE), leading to higher operating voltage and higher energy density for PIBs. [10][11][12] However, it is still a great challenge to develop appropriate electrode materials to accommodate the larger K + compared to Li + and Na + .

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A Promising Carbon/g‐C3N4 Composite Negative Electrode for a Long‐Life Sodium‐Ion Battery

“…We demonstrate that an extremely high Coulombic efficiency( CE, > 99.9 %) and negligible capacity fading are achieved for this Na half cell ( Figure 4F). To provide af ull picture of this as-prepared C/g-C 3 N 4 negative electrode,w et hen evaluate it in af ull cell device ( Figure 5A)inwhich sodium rhodizonate dibasic (Na 2 C 6 O 6 ), ap romising organic electrode, [34] is used as the positive electrode.The characterization of the as-prepared Na 2 C 6 O 6 is shown in the Supporting Information, Figure S8. To provide af ull picture of this as-prepared C/g-C 3 N 4 negative electrode,w et hen evaluate it in af ull cell device ( Figure 5A)inwhich sodium rhodizonate dibasic (Na 2 C 6 O 6 ), ap romising organic electrode, [34] is used as the positive electrode.The characterization of the as-prepared Na 2 C 6 O 6 is shown in the Supporting Information, Figure S8.…”