No abstract

Aqueous zinc metal batteries have garnered unprecedented attention owing to their high theoretical specific capacity, appropriate redox potential, and remarkable sustainability. Nevertheless, the intractable issues induced by the notorious Zn dendrite growth and serious interfacial side reactions significantly impede their large‐scale utilization. Inducing Zn to electrodeposit through parallel arrangement mode is critical to realizing dendrite‐free Zn metal anodes (ZMAs). To realize this purpose, a unique polymeric molecular design strategy through chemically grafting a thin polyanthraquinone (PAQ) overlayer on the Zn surface in the manner of spontaneous polymerization reaction of anthraquinone diazonium tetrafluoroborate (AQN2+BF4−) is proposed firstly. Impressively, thus‐derived PAQ overlayer as an artificial protective layer can constrain the Zn2+ ions 2D diffusion and homogenize the electric field and Zn2+ ions concentration distribution, further guiding preferential growth along the Zn(002) plane. Assisted by the PAQ overlayer, the dendrite growth, H2 evolution reaction, and Zn corrosion on ZMAs are suppressed effectively. Accordingly, such polymeric molecular modified ZMAs ensure a remarkably high Coulombic efficiency of 99.7% at 4 mA cm−2 and achieve a long cycling lifespan up to 1750 h at 1 mA cm−2 and superior rate capability. This work provides a new insight into designing an interface protective layer for achieving highly stable ZMAs.

Uncontrolled dendrites growth and serious parasitic reactions in aqueous electrolytes, greatly hinder the practical application of aqueous zinc-ion battery. On the basis of in situ-chemical construction and performance-improving mechanism, multifunctional fluoroethylene carbonate (FEC) is introduced into aqueous electrolyte to construct a high-quality and ZnF 2 -riched inorganic/organic hybrid SEI (ZHS) layer on Zn metal anode (ZMA) surface. Notably, FEC additive can regulate the solvated structure of Zn 2 + to reduce H 2 O molecules reactivity. Additionally, the ZHS layer with strong Zn 2 + affinity can avoid dendrites formation and hinder the direct contact between the electrolyte and anode. Therefore, the dendrites growth, Zn corrosion, and H 2 evolution reaction on ZMA in FEC-included ZnSO 4 electrolyte are highly suppressed. Thus, ZMA in such electrolyte realize a long cycle life over 1000 h and deliver a stable coulombic efficiency of 99.1 % after 500 cycles.

3D carbon hosts can enable low‐stress Li metal anodes (LMAs) with improved structural and interfacial stability. However, the uneven Li+ flux and large concentration polarization, resulting from intrinsically poor Li affinity and limited porosity of carbon scaffolds, make the precise control of Li plating/stripping still one the key challenges facing advanced LMAs. Here it is demonstrated that a lightweight carbon scaffold, featuring parallel‐aligned porous fibers, can work well for homogeneous Li+ flux distribution and reduced concentration gradient to form a stable solid electrolyte interphase, and then synergistically guide smooth Li nucleation/growth even at low temperatures. As a result, the obtained LMAs delivers a high areal capacity up to 15 mAh cm−2, ultralong lifespan (4800 cycles at 4 mA cm−2) with very low voltage hysteresis of ≈21 mV, a high practically available specific capacity of 863.9 mAh g−1 after 1000 cycles, and a long‐term stable behavior at low‐temperature operation. As coupling with the commercial LiNi1/3Co1/3Mn1/3O2 cathodes and common carbonate‐based electrolyte, the corresponding practical cells also possess an ultralong lifespan and outstanding low‐temperature functionality. This study not only presents an advanced carbon host candidate but also sheds new light on crucial design principles of carbon scaffolds for practically feasible rechargeable metal batteries.

Lithium (Li) metal is a promising anode material due to its high theoretical capacity (3860 mA h g–1) and lowest electrochemical potential. Nevertheless, the uncontrollable growth of Li dendrites and the infinite volume change during cycling restrict the practical applications of lithium metal batteries (LMBs). Herein, a dandelion-like host material, which is composed of a N-doped porous core with lithiophilic Co nanoparticles implanted into 3D carbon nanotubes (defined as Co@NPC), is developed to enable dendrite-free hybrid lithium metal anodes (HLMAs) even at high current density. The porous N-doped carbon polyhedron core inserted by lithiophilic Co nanoparticles provides high specific surface area and enriched nucleation sites to guide smooth lithium nucleation and deposition in the core with decreased nucleation barrier. Simultaneously, the nanochannel confinement effect of 3D carbon nanotubes inhibits the growth of dendrites and induces Li deposition into the internal space homogeneously. In virtue of the unique nanoarchitecture construction, the HLMA delivers superior Coulombic efficiency (98.3%) at a high current density of 5 mA cm–2 and exhibits ultralong lifespan (1000 cycles) with ultralow hysteresis voltage (31 mV) even at 10 mA cm–2. This work sheds light on designing and developing an advanced and scalable host for LMAs toward stable LMBs to be practical and feasible.