Dual‐Graphene Rechargeable Sodium Battery

Abstract

Sodium (Na) ion batteries are attracting increasing attention for use in various electrical applications. However, the electrochemical behaviors, particularly the working voltages, of Na ion batteries are substantially lower than those of lithium (Li) ion batteries. Worse, the state-of-the-art Na ion battery cannot meet the demand of miniaturized in modern electronics. Here, we demonstrate that electrochemically exfoliated graphene (EG) nanosheets can reversibly store (PF ) anions, yielding high charging and discharging voltages of 4.7 and 4.3 V vs. Na /Na, respectively. The dual-graphene rechargeable Na battery fabricated using EG as both the positive and negative electrodes provided the highest operating voltage among all Na ion full cells reported to date, together with a maximum energy density of 250 Wh kg . Notably, the dual-graphene rechargeable Na microbattery exhibited an areal capacity of 35 μAh cm with stable cycling behavior. This study offers an efficient option for the development of novel rechargeable microbatteries with ultra-high operating voltage and high energy density.

Penne‐Like MoS2/Carbon Nanocomposite as Anode for Sodium‐Ion‐Based Dual‐Ion Battery

“…Furthermore, Figure e shows the long‐term cycling stability of the MoS 2 /C‐G DIB at 2 C for 200 cycles with MoS 2 ‐G DIB as contrast. The discharge capacity remained stable with a capacity of 55 mA h g −1 after 200 cycles and 85% capacity retention, demonstrating good cycling performance of the MoS 2 /C‐G DIB, which is superior than most reported DIBs based on sodium‐ion electrolytes . The coulombic efficiency also kept at around 90% during 200 cycles apart from the first several cycles.…”

“…Sodium‐ion batteries (SIBs) have attracted more and more attention in the past decades owing to the merits of low cost and large earth abundance . However, sodium‐ion based DIBs were rarely investigated due to the larger size of Na + (1.4 times larger than Li + ), leading to failure of Na + intercalation/deintercalation into/from graphite anode. Therefore, designing appropriate anode materials plays an important role on developing high‐performance Na‐DIBs.…”

Electrolytes for Dual‐Carbon Batteries

“…evaluated the ether‐based electrolyte (2 M NaPF 6 in diethylene glycol dimethyl ether (DEGDME) with 1 % (C 3 HF 6 O) 3 PO as additive) for a DCB with graphene as both cathode and anode. The DCB can be charged to 4.5 V and delivered a specific capacity of 68 mAh g −1 based on the total mass of electrodes at a specific current of 50 mA g −1 . In an attempt to take full advantage of ether‐based electrolytes, an innovative dual‐organic electrolyte (IL–ether hybrid electrolyte) has been designed for dual‐graphite batteries by Qiao et al .…”

“…The DCB can be charged to 4.5 V and delivered a specific capacity of 68 mAh g À 1 based on the total mass of electrodes at a specific current of 50 mA g À 1 . [111] In an attempt to take full advantage of ether-based electrolytes, an innovative dual-organic electrolyte (IL-ether hybrid electrolyte) has been designed for dual-graphite batteries by Qiao et al [112] The LiTFSI-triethylene glycol dimethyl ether (1 : 1 molar ratio) electrolyte on the anode ensures a high reversibility of Li + de-/ intercalation, while the 1.5 M LiTFSI-Pyr 13 TFSI electrolyte within the cathodic side can endure high potentials. A Nafion-based separator was applied to restrain mutual diffusion between these electrolytes (Figure 8a).…”

Miniaturized Energy Storage Devices Based on Two‐Dimensional Materials

“…These features make 2D materials very attractive electrode materials for MESDs. The 2D materials reported for MB cathode materials include graphene‐based composites, intercalation compounds (e.g., LiCoO 2 nanosheets), 2D organic polymers (e.g., polypyrrole (PPy) nanosheets), whereas the anode materials often contain graphene, transition‐metal dichalcogenides (TMDs), and MXene, together with 2D transition‐metal oxides (TMOs; e.g., V 2 O 5 nanosheets). Typical 2D materials used in MBs could also be applied in MSCs .…”