Aluminum battery systems are considered as a system that could supplement current lithium batteries due to the low cost and high volumetric capacity of aluminum metal, and the high safety of the whole battery system. However, first the use of ionic liquid electrolytes leading to AlCl4− instead of Al3+, the different intercalation reagents, the sluggish solid diffusion process and the fast capacity fading during cycling in aluminum batteries all need to be thoroughly explored. To provide a good understanding of the opportunities and challenges of the newly emerging aluminum batteries, this Review discusses the reaction mechanisms and the difficulties caused by the trivalent reaction medium in electrolytes, electrodes, and electrode–electrolyte interfaces. It is hoped that the Review will stimulate scientists and engineers to develop more reliable aluminum batteries.

Low‐dimensional materials have been long sought after for their particular electromagnetic (EM) functions, with promising applications in EM wave absorbing and shielding, communicating and imaging, sensing and detecting, driving and actuating, etc. Herein, across the whole EM spectrum, low‐dimensional EM functional materials and devices are highly focused on. The crystal engineering and function‐guiding features addressed relate to crystal and electronic structures, EM responses and properties, energy conversion, as well as EM wave absorbing and shielding. Moreover, insight is given into this rapidly broadening field, the main challenges are proposed and future directions are predicted.

The microwave absorption, electromagnetic interference shielding, and microwave response mechanism of graphene hybrids are highlighted, including relaxation, charge transport, magnetic resonance,etc.

The lithium metal anode is considered as the ultimate choice for high-energy-density batteries. However, the organic-dominated solid electrolyte interphase (SEI) formed in carbonate electrolytes has a low interface energy against metallic Li as well as a high resistance, resulting in a low Li plating/stripping Coulombic efficiency (CE) of less than 99.0% and severe Li dendrite growth. Herein, inorganic-enhanced LiF-Li3N SEI is designed in commercial 1 M LiPF6/EC-DMC electrolytes by introducing lithium nitrate (LiNO3) and fluoroethylene carbonate (FEC) through a small amount of sulfolane (SL) as a carrier solvent owing to the high solubility of SL for both carbonate solvents and LiNO3. The comprehensive characterizations and simulations demonstrate that the synergistic interaction of LiNO3 and FEC additives alters the solvation structure of 1 M LiPF6/EC-DMC electrolytes and forms additive-derived LiF-Li3N SEI, which increases the average Li CE up to 99.6% in 100 cycles. The designed carbonate electrolyte enables the Li/LiNi0.80Co0.15Al0.05O2 (NCA) cell with a lean lithium metal anode (∼50 μm) to achieve an average CE of 99.7% and a high capacity retention of 90.8% after 150 cycles. This work offers a simple and economical strategy to realize high-performance lithium metal batteries in commercial carbonate electrolytes.

We fabricated NiO nanorings on SiC, a novel hierarchical architecture, by a facile two-step method. The dielectric properties depend on temperature and frequency in the range from 373 to 773 K and X band. The imaginary part and loss tangent increase more than four times and three times with increasing temperature, respectively. The architecture demonstrates multirelaxation and possesses high-efficient absorption. The reflection loss exceeds -40 dB and the bandwidth covers 85% of X band (approximately -20 dB). The synergistic effect between multirelaxation and conductance is beneficial to the microwave absorption. Our findings provide a novel and feasible strategy to tune microwave absorption.

The Gerson-Marshall (1959) relationship predicts an increase in dielectric breakdown strength (BDS) and therefore, recoverable energy density (Wrec) with decreasing dielectric layer thickness. This relationship only operates however, if the...

The electrochemical performance of the aluminum-sulfur (Al-S) battery has very poor reversibility and a low charge/discharge current density owing to slow kinetic processes determined by an inevitable dissociation reaction from Al Cl to free Al . Al Cl Br was used instead of Al Cl as the dissociation reaction reagent. A 15-fold faster reaction rate of Al Cl Br dissociation than that of Al Cl was confirmed by density function theory calculations and the Arrhenius equation. This accelerated dissociation reaction was experimentally verified by the increase of exchange current density during Al electro-deposition. Using Al Cl Br instead of Al Cl , a kinetically accelerated Al-S battery has a sulfur utilization of more than 80 %, with at least four times the sulfur content and five times the current density than that of previous work.

anode is approaching the theoretical capacity of 372 mAh g −1 and cannot satisfy the growing demand. Moreover, graphite anode undergoes severe capacity degradation and uncontrolled Li plating rather than Li intercalation below 0 °C. [2] Li metal anode, with high theoretical capacity of 3860 mAh g −1 and operational plating/ stripping at low temperatures, has been considered as the most promising candidate for high-energy-density batteries. Nevertheless, practical application of Li anode has been hampered by its uncontrollable dendrite electrodeposition, which lowers the Coulombic efficiency (CE) by reacting with electrolytes to form solid electrolyte interphase (SEI) and deteriorates the structure of Li metal batteries. [3] Unlike graphite anode with stable SEI during charging, the volume expansion of dendrite growth induces rupture of the fragile SEI film during plating/stripping. [4] The fresh exposed Li causes continuous electrolyte decomposition, together with forming thick SEI film. Such SEI has low ion conductivity and high concentration polarization, resulting in uneven Li + flux and uncontrollable dendrite growth. [5] As temperature decreases, the increased ion desolvation barrier further exacerbates the dendrite formation and short-circuiting of the battery. [6] During discharging, the Li + desolvation at cathode increases the polarization and reduces the discharging capacity, especially at low temperature. The ion-dipole chemistry is important for Li metal batteries, because it can directly impact the process of the Li + desolvation and the formation of a passivation layer, resulting in uniform Li deposition and high energy density.The formation of Li + solvation sheath is the competition between cation-anion, cation-dipole, and dipole-dipole interactions. [7] Because the charge density is localized on small Li + (0.09 nm), the Li + -dipole interaction is far stronger than the interaction between Li + and the anion. [8] Hence, most studies focus on reducing the ratio of solvent-to-anion in the Li + solvation sheath or weakening the interaction strength between the Li + and dipole for fast Li + desolvation and subsequent SEI formation. To enhance the participation of anions in the solvation sheath, lithium trifluoroacetate (LiTFA) coordinated with Li + by strong polar groups (CO) has been used to regulate the solvation structure and enable low Li + desolvation energy. [9] Combined with fluoroethylene carbonate (FEC), [10] Sluggish evolution of lithium ions' solvation sheath induces large chargetransfer barriers and high ion diffusion barriers through the passivation layer, resulting in undesirable lithium dendrite formation and capacity loss of lithium batteries, especially at low temperatures. Here, an ion-dipole strategy by regulating the fluorination degree of solvating agents is proposed to accelerate the evolution of the Li + solvation sheath. Ethylene carbonate (EC)-based fluorinated derivatives, fluoroethylene carbonate (FEC) and di-fluoro ethylene carbonate (DFEC) are used as the solvating a...