No abstract

Aqueous zinc‐ion battery (AZIB) has become a promising candidate in grid energy storage due to its low cost, environmental friendliness, and high safety. However, AZIB usually suffers from uncontrollable zinc deposition and dendrite growth as well as hydrogen evolution and passivation on the surface of zinc anode. To address the above issues, a unique 3D Zn alloy foam anode built from Zn–Sn–Pb alloy in 3D Cu foam is constructed by a facile hot dipping method. The proposed 3D Zn alloy anode, through introducing elements Sn and Pb, enhances the hydrogen evolution overpotential, reduces the corrosion current, greatly mitigates the self‐corrosion in the electrolyte, and efficiently inhibits the growth of Zn dendrite during cycling. Importantly, such Zn alloy engineering together with a 3D Cu foam current collector enables highly stable Zn storage properties. The full cell assembled using the proposed 3D Zn alloy anode and MnO2 nanosheet cathode exhibits superior reversible capacity (103.4 mAh g−1) and excellent cycling stability (capacity retention of 87% over 4000 cycles) at 1.8 A g−1.

M–Nb–O compounds have been considered as promising anode materials for lithium-ion batteries (LIBs) because of their high capacities, safety, and cyclic stability. However, very limited M–Nb–O anode materials have been developed thus far. Herein, GaNb11O29 with a shear ReO3 crystal structure and a high theoretical capacity of 379 mAh g–1 is intensively explored as a new member in the M–Nb–O family. GaNb11O29 nanowebs (GaNb11O29-N) are synthesized based on a facile single-spinneret electrospinning technique for the first time and are constructed by interconnected GaNb11O29 nanowires with an average diameter of ∼250 nm and a large specific surface area of 10.26 m2 g–1. This intriguing architecture affords good structural stability, restricted self-aggregation, a large electrochemical reaction area, and fast electron/Li+-ion transport, leading to a significant pseudocapacitive behavior and outstanding electrochemical properties of GaNb11O29–N. At 0.1 C, it shows a high specific capacity (264 mAh g–1) with a safe working potential (1.69 V vs Li/Li+) and the highest first-cycle Coulombic efficiency in all of the known M–Nb–O anode materials (96.5%). At 10 C, it exhibits a superior rate capability (a high capacity of 175 mAh g–1) and a durable cyclic stability (a high capacity retention of 87.4% after 1000 cycles). These impressive results indicate that GaNb11O29-N is a high-performance anode material for LIBs.

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The surface of neutron-rich heavy nuclei, with a neutron skin created by excess neutrons, provides an important terrestrial model system to study dilute neutron-rich matter. By using quasi-free α cluster–knockout reactions, we obtained direct experimental evidence for the formation of α clusters at the surface of neutron-rich tin isotopes. The observed monotonous decrease of the reaction cross sections with increasing mass number, in excellent agreement with the theoretical prediction, implies a tight interplay between α-cluster formation and the neutron skin. This result, in turn, calls for a revision of the correlation between the neutron-skin thickness and the density dependence of the symmetry energy, which is essential for understanding neutron stars. Our result also provides a natural explanation for the origin of α particles in α decay.