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.
Xueting Huang,Jiaxin Wen,Jinglei Lei,Guangsheng Huang,Fusheng Pan,Lingjie Li
A cost-effective and highly efficient electrolyte with a wide electrochemical window, high reversibility of Mg plating/stripping, non-/low-corrosivity, good compatibility with cathode materials, and tolerance of trace water and impurity is crucial for the commercialization of rechargeable magnesium batteries. In this work, a novel boron-centered non-nucleophilic electrolyte that meets all the above requirements is prepared via a facile and economic approach from the raw materials B(TFE)3/MgCl2/CrCl3/Mg (BMCM). The as-prepared BMCM electrolyte is mainly composed of tetracoordinated anions [B(TFE)4]− and solvated cations [Mg2(μ-Cl)2(DME)4]2+. The BMCM electrolyte demonstrates attractive electrochemical performance, with a low overpotential (∼139 mV), a high Coulombic efficiency (∼97%), a high anodic stability (∼3.5 V vs Mg/Mg2+), and a long-term (more than 500 h) cycling stability. Moreover, BMCM shows good compatibility with the CuS cathode material. The CuS|BMCM|Mg full cell delivers a discharge specific capacity of 231 mAh g–1 (at 56 mA g–1), which can retain ∼88% even after 100 cycles. Importantly, the BMCM electrolyte is cost-effective and tolerant of trace impurity and water, which has great potential to be commercialized. This work is expected to promote the development of practical rechargeable magnesium batteries.