Aqueous Zn-ion batteries (AZIBs) have been recognized as promising energy storage devices due to their high theoretical energy density and cost-effectiveness. However, side reactions and Zn dendrite generation during cycling limit their practical application. Herein, ammonium acetate (CH 3 COONH 4 ) is selected as a trifunctional electrolyte additive to enhance the electrochemical performance of AZIBs. Research findings show that NH 4 + (oxygen ligand) and CH 3 COO -(hydrogenligand) with preferential adsorption on the Zn electrode surface can not only hinder Zn anode directly contact with active H 2 O, but also regulate the pH value of the electrolyte, thus suppressing the parasitic reactions. Additionally, the formed SEI is mainly consisted of Zn 5 (CO 3 ) 2 (OH) 6 with a high Zn 2+ transference number, which could achieve a dendrite-free Zn anode by homogenizing Zn deposition. Consequently, the Zn||Zn symmetric batteries with CH 3 COONH 4 -based electrolyte can operate steadily at an ultrahigh current density of 40 mA cm -2 with a cumulative capacity of 6880 mAh cm -2 , especially stable cycling at −10 °C. The assembled Zn||MnO 2 full cell and Zn||activated carbon capacitor also deliver prominent electrochemical reversibility. This work provides unique understanding of designing multi-functional electrolyte additive and promotes a long lifespan at ultrahigh current density for AZIBs.

Sodium/potassium-ion batteries (SIBs/PIBs) are supposed to replace the conventional lithium-ion batteries (LIBs) in the near future in view of their lower cost and abundant reserves of sodium/potassium resources. Nowadays, it...

Herein, we report a charge-transfer complex electrolyte additive, 7,7,8,8-tetracyanoquinodimethane (TCNQ), with high Zn affinity, which was tightly adsorbed on the surface of a Zn anode to form a dense and robust interfacial complex layer and suppress the activity of H2O. As verified by comprehensive experimental and computational analyses, this complex layer could construct a Zn–Zn(TCNQ)2 Ohmic contact interface, guide rapid ion/electron transport, ameliorate electric field distribution, and inhibit the direct contact between the active H2O and Zn anode, demonstrating a dendrite-free Zn anode and facile Zn plating/stripping kinetics. Consequently, the Zn||Zn symmetrical cell exhibits a high Zn plating/stripping reversibility of over 1000 h at 20 mA cm–2 and 5 mA h cm–2 and a high depth of discharge (43%). Moreover, the Zn||MnO2 full cell delivers a high capacity of 143.3 mA h g–1 at 2000 mA g–1 even after 4000 cycles and a capacity retention of 94.7% after returning to 100 mA g–1.

Developing electrodes with long lifespan and wide‐temperature adaptability is crucial important to achieve high‐performance sodium/potassium‐ion batteries (SIBs/PIBs). Herein, the SnSe2‐SePAN composite was fabricated for extraordinarily stable and wide‐temperature range SIBs/PIBs through a coupling strategy between controllable electrospinning and selenylation, in which SnSe2 nanoparticles were uniformly encapsulated in the SePAN matrix. The unique structure of SnSe2‐SePAN not only relieves drastic volume variation but also guarantees the structural integrity of the composite, endowing SnSe2‐SePAN with excellent sodium/potassium storage properties. Consequently, SnSe2‐SePAN displays a high sodium storage capacity and excellent feasibility in a wide working temperature range (−15 to 60°C: 300 mAh g−1/700 cycles/−15°C; 352 mAh g−1/100 cycles/60°C at 0.5 A g−1). At room temperature, it delivers a record‐ultralong cycling life of 192 mAh g−1 that exceeds 66 000 cycles even at 15 A g−1. It exhibits extremely superb electrochemical performance in PIBs (157 mAh g−1 exceeding 15 000 cycles at 5 A g−1). The ex situ XRD and TEM results attest the conversion‐alloy mechanism of SnSe2‐SePAN. Also, computational calculations verify that SePAN takes an important role in intensifying the electrochemical performance of SnSe2‐SePAN electrode. Therefore, this study breaks new ground on solving the polyselenide dissolution issue and improving the wide temperature workable performance of sodium/potassium storage.

Metal 1T phase molybdenum disulfide (1T-MoS2) is being actively considered as a promising anode due to its high conductivity, which can improve electron transfer. Herein, we elaborately designed stable Sb-doped...