A High‐Rate Rechargeable Mg Battery Based on AgCl Conversion Cathode with Fast Solid‐State Mg²⁺ Diffusion Kinetics

Abstract

Rechargeable Mg batteries are attractive candidates for large‐scale energy storage batteries with high safety due to the low‐cost and non‐dendritic metallic Mg anode. However, exploring high‐performance cathode materials is blocking their development. Herein, a high‐rate rechargeable Mg battery is established with a AgCl cathode, delivering a high reversible capacity of 70.3 mAh g−1 at 100 mA g−1, an outstanding rate capability of 32.6 mAh g−1 at 1000 mA g−1, and a superior long‐term cyclability over 500 cycles. Further investigation of the mechanism demonstrates that a conversion reaction takes place between AgCl and metallic Ag0 for the cathode. The solid‐state Mg2+ diffusion coefficient is as high as 8.1 × 10−11 cm2 s−1, which would be the reason for the high rate capability. The current study reveals significant insights to select promising Mg‐storage conversion cathodes by a combination of soft anions and soft transition‐metal cations.

Rechargeable Mg2+/Li+, Mg2+/Na+, and Mg2+/K+ Hybrid Batteries Based on Layered VS2

“…The GITT discharge/charge curves of Mg 2+ /Li + , Mg 2+ /Na + , and Mg 2+ /K + cells are displayed in Figure 7a,c,e, respectively, and the corresponding ion diffusivities calculated are listed in Figure 7b,d,f (details are given in the Supporting Information). 42 As shown in Figure 7b, the average Li + diffusion coefficients are generally at the levels of 1.0 × 10 −12 −1.0 × 10 −8 (charge process) and 1.0 × 10 −11 −1.0 × 10 −8 cm 2 s −1 (discharge process), which agree well with previous reports. 39 Apart from the insertion of Ph 2 Mg and THF, our work suggests that the irreversible Mg 2+ insertion during Mg 2+ /Li + co-intercalation could do the same work of accelerating Li + diffusion.…”

Self-sufficient self-oscillating microsystem driven by low power at low Reynolds numbers

“…The power consumption of our system compares to a running ant that consumes ~86 μW of metabolic power (~1 mcal each minute) ( 11 ) or a swimming calanoid copepod plankton that consumes about ~100 μW (~1.4 mcal each minute) ( 12 ). Furthermore, the system is powered either by an external power source or an embedded Ag-Mg battery ( 13 ). The latter provides autonomy and biocompatibility as Ag and Mg have previously been used safely in subcutaneous batteries and implants ( 14 , 15 ).…”

From Cathodes to Conductive Pastes: A New Perspective into the Recycle of Silver Element

“…[ 22 ] More recently, Xu et al established a rechargeable Mg battery based on AgCl cathodes, delivering a reversible capacity of 55 mA h g −1 after 100 cycles at 100 mA g −1 . [ 23 ] However, these batteries suffered from poor cyclability due to the large volume change and sluggish kinetics of electrodes. Another disadvantage is that the electrolyte of these batteries is a nonaqueous solvent, which brings higher cost and safety risk.…”