Sulfide solid electrolytes with high conductivity that is close to that of liquid electrolyte have been considered to be one of the most promising electrolytes for all-solid-state lithium batteries (ASSLBs). Unfortunately, the narrow electrochemical windows of sulfide electrolyte and contact loss at the interface upon cycles much limits the application of sulfide-based ASSLBs. In this work, an organic quinone cathode, 5,7,12,14-pentacenetetrone (PT), is used to fabricate an ASSLB with a sulfide electrolyte of glass ceramic 70Li 2 S-30P 2 S 5 (LPS). Based on the various in situ/ex situ analyses, it is successfully demonstrated that the decomposition of LPS is negligible and the corresponding effects on interfacial impedance are reversible with optimized carbon additives. In addition, the inherent low Young's modulus of the PT electrode efficiently prevents the contact loss at the interface. As a result, the PT-based ASSLBs deliver a high specific capacity (312 mAh g −1 ) and an excellent capacity retention (90.6%) over 500 cycles which is superior to previous reports. Moreover, a carbon-free ASSLB is constructed by employing Mo 6 S 8 as conductive additives in a PT-based cathode, which shows an improved rate performance and a long life.
Lin Zirui,Shi Hua-Yu,Lin Lu,Yang Xianpeng,Wu Wanlong,Sun Xiaoqi
Rechargeable aqueous zinc-organic batteries are promising energy storage systems with low-cost aqueous electrolyte and zinc metal anode. The electrochemical properties can be systematically adjusted with molecular design on organic cathode materials. Herein, we use a symmetric small molecule quinone cathode, tetraamino-p-benzoquinone (TABQ), with desirable functional groups to protonate and accomplish dominated proton insertion from weakly acidic zinc electrolyte. The hydrogen bonding network formed with carbonyl and amino groups on the TABQ molecules allows facile proton conduction through the Grotthuss-type mechanism. It guarantees activation energies below 300 meV for charge transfer and proton diffusion. The TABQ cathode delivers a high capacity of 303 mAh g −1 at 0.1 A g −1 in a zinc-organic battery. With the increase of current density to 5 A g −1 , 213 mAh g −1 capacity is still preserved with stable cycling for 1000 times. Our work proposes an effective approach towards high performance organic electrode materials.
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.