Tan Meina,Qin Yang,Wang Yiping,Zhang Fazhi,Lei Xiaodong
We propose a new Cu–Al dual-ion battery that aqueous solution composed of LiCl, CuCl and AlCl 3 (LiCuAl) is used as the electrolyte, CuS is used as the cathode of aqueous aluminum ion battery for the first time and copper foil is used as the anode. The assembled Cu–Al dual-ion battery yields a reversible capacity of 538 mA h/g at 200 mA/g, and exhibits longterm cycling stability of over 200 cycles with 88.6% capacity retention at 1000 mA/g. Above excellent performance is inseparable from the three components of LiCuAl electrolyte and electrode materials. The Al-storage mechanism of CuS is proposed that the S–S bond in CuS lattice interacts with aluminum ions during the aluminum storage process. In addition, the charging and discharging process does not cause irreversible damage to the S–S bond, thus Cu–Al dual-ion battery with CuS as cathode shows great cycle stability.
Xuejun Zhou,Guyue Li,Yifan Yu,Meng Lei,Keyi Chen,Chilin Li
Magnesium metal batteries (MMBs) currently face challenges suffering from severe Mg metal passivation and extremely high overpotential in conventional electrolytes. Herein, a strategy of using a low-cost deep eutectic solution (DES) is proposed to modify Mg anode with the monolithic and compact coating of a MgCl 2 -Al-MgCl 2 sandwich structure, enabling the stable and reversible Mg plating–stripping behavior. An organic/nanocrystal hybrid interphase is in-situ built through a facile Mg-Al displacement reaction between aluminum-chloro clusters and Mg in AlCl 3 /Et 3 NHCl solution, and it can effectively minimize the adverse interfacial passivation reaction and surface diffusion barrier, affording the high ion-conduction and electronic insulation. This DES-assisted method guarantees a highly reversible cycling of Mg metal anode (over 5000 h at 0.1 mA cm −2 and 400 h at 2.0 mAh cm −2 ) in Mg(TFSI) 2 /DME electrolyte with the improved interfacial kinetics and low overpotential. Even at a much higher current density of 1 mA cm −2 , the overpotential only undergoes a slight increase from 0.2 V (at 0.1 mA cm −2 ) to 0.23 V. The corresponding full cells with CuS and phenanthraquinone cathodes deliver satisfactory cyclic performance. The DES modification strategy provides a new solution to the design of robust and conductive solid electrolyte interphase for achieving high-voltage and durable MMBs.