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Anion-intercalation lithium metal batteries (AILMBs) are appealing due to their low cost and fast intercalation/de-intercalation kinetics of graphite cathodes. However, the safety and cycliability of existing AILMBs are constrained by the scarcity of compatible electrolytes. Herein, we showcase that a difluoroester can be applied as electrolyte solvent to realize high-performance AILMBs, which not only endows high oxidation resistance, but also efficiently tunes the solvation shell to enable highly reversible and kinetically fast cathode reaction beyond the trifluoro counterpart. The difluoroester-based electrolyte demonstrates nonflammability, high ionic conductivity, and electrochemical stability, along with excellent electrode compatibility. The Li| |graphite AILMBs reach a high durability of 10000 cycles with only a 0.00128% capacity loss per cycle under fast-cycling of 1 A g−1, and retain ~63% of room-temperature capacity when discharging at −65 °C, meanwhile supply stable power output under deformation and overcharge conditions. The electrolyte design paves a promising path toward fast-rate, low-temperature, durable, and safe AILMBs. The authors report a difluoroester electrolyte to enhance anion intercalation lithium metal batteries (AILMBs), improving safety and cyclability. This enables cost-effective graphitic carbon cathodes, with high durability, stability, and performance. [ABSTRACT FROM AUTHOR]

Metal–metal battery bears great potential for next‐generation large‐scale energy storage system because of its simple manufacture process and low production cost. However, the cross‐over of metal cations from the cathode to the anode causes a loss in capacity and influences battery stability. Herein, a coating of poly (ionic liquid) (PIL) with poly(diallyldimethylammonium bis(trifluoromethanesulfonyl)imide) (PDADMA+TFSI−) on a commercial polypropylene (PP) separator serves as an anion exchange membrane for a 3.3 V copper–lithium battery. The PIL has a positively charged polymer backbone that can block the migration of copper ions, thus improving Coulombic efficiency, long‐term cycling stability and inhibiting self‐discharge of the battery. It can also facilitate the conduction of anions through the membrane and reduce polarization, especially for fast charging/discharging. Bruce‐Vincent method gives the transport number in the electrolyte to be 0.25 and 0.04 for PP separator without and with PIL coating, respectively. This suggests that the PIL layer reduces the contribution of the internal current due to cation transport. The use of PIL as a coating layer for commercial PP separator is a cost‐effective way to improve overall electrochemical performance of copper–lithium batteries. Compared to PP and polyacrylic acid(PAA)/PP separators, the PIL/PP membrane raises the Coulombic efficiency to 99% and decreases the average discharge voltage drop to about 0.09 V when the current density is increased from 0.1 to 1 mA cm−2. [ABSTRACT FROM AUTHOR]

Tin (Sn) is a common metal in our daily life. Recently, Sn and its alloys have received much interest as anode materials for lithium-ion batteries. Herein, we are the first to demonstrate a Sn–Li battery using Sn metal as the cathode and Li metal as the anode in a carbonate–ether based electrolyte. The Sn–Li battery uses electrochemical redox reactions of the two metal/metal cation pairs to store and release energy. With an anion exchange membrane as the separator, the battery can cycle at a current density of 0.2 mA cm−2 with an areal capacity limitation of 0.1 mA h cm−2 and a discharge voltage of about 2.8 V for more than 1500 cycles with an average Coulombic efficiency of about 99.5%. The discharge voltage plateau of the Sn–Li battery drops by only 0.05 V even when the current density is increased 5 times to 1 mA cm−2 (about a 10C rate), demonstrating its fast kinetics. Comparing batteries with Sn, Cu and Ni cathodes, the ones with Sn and Cu show lower activation energy for the redox reaction and smaller polarization than that with Ni. On the other hand, Sn and Ni show higher average Coulombic efficiency than that of Cu, suggesting smaller permeability of Sn2+ and Ni2+ than Cu+ through the PIL/PP membrane. Overall, Sn shows better performance over Cu and Ni as the cathode material for metal–metal batteries. [ABSTRACT FROM AUTHOR]

The dual‐ion battery (DIB) is a promising energy storage system that demonstrates high‐power characteristics and fast‐charging capability. However, conventional electrolytes are not compatible with the high‐voltage graphite cathode and the reactive Li metal anode, thus leading to the poor cycle stability and low Coulombic efficiency of the DIB. Here, an all‐fluorinated electrolyte is reported that can enable a highly stable operation of the graphite||Li DIB up to 5.2 V by forming robust and less‐resistive passivation films on both electrodes to reduce side reactions. The electrolyte allows reversible PF6– anion insertion/extraction and Li+ cation plating/stripping in the graphite||Li battery, achieving stable cycling with 94.5% capacity retention over 5000 cycles at 500 mA g–1, high capacity utilization of 91.8% of the available charge capacity at 50 C (5000 mA g–1), and also minimal self‐discharge. At a low temperature of 0 °C, this all‐fluorinated electrolyte exhibits 97.8% of the room temperature reversible capacity, along with ≈100% capacity retention after more than 3000 cycles, at 5 C. This work sheds a new light on the development of fluorinated electrolytes for high voltage and long‐lasting DIBs. [ABSTRACT FROM AUTHOR]

While sodium-ion batteries (SIBs) are considered as a next-generation energy storage device because of the higher abundance and lower cost of sodium compared to those of lithium, developing high-power and stable cathode materials remains a great challenge. Here, micron-sized plate-like copper-substituted layered P2-type Na0.67CuxMn1−xO2 is demonstrated to rapidly charge and discharge within 5 minutes while giving a capacity of more than 90 mA h g−1, corresponding to a half-cell energy density of 260 W h (kg cathode)−1 at a power density of 3000 W (kg cathode)−1, which is comparable to that of high-power lithium-ion cathodes. The materials show excellent stability, retaining more than 70% of the initial capacity after 500 cycles at 1000 mA g−1. The good cycle and rate performances of the materials are attributed to copper in the lattice, which stabilizes the crystal structure, increases the average discharge potential and improves sodium transport. This makes Na0.67CuxMn1−xO2 an ideal choice as a cathode for high-power sodium-ion batteries. [ABSTRACT FROM AUTHOR]

Dual‐Ion Batteries In article number 2103360, Denis Y. W. Yu and co‐workers report the development of an all‐fluorinated electrolyte which enables highly reversible PF6− and Li+ storage towards high performance dual‐ion batteries (DIBs). Because of its high‐power capability, the DIB is suitable for modulating power supply and the demands of renewables, and for fast‐charging of electric buses within minutes. [ABSTRACT FROM AUTHOR]

Dual-ion batteries, fluorinated electrolytes, high voltage, PF 6- intercalation, surface protection An All-Fluorinated Electrolyte Toward High Voltage and Long Cycle Performance Dual-Ion Batteries (Adv. Keywords: dual-ion batteries; fluorinated electrolytes; high voltage; PF 6- intercalation; surface protection EN dual-ion batteries fluorinated electrolytes high voltage PF 6- intercalation surface protection 1 1 1 05/23/22 20220519 NES 220519 B Dual-Ion Batteries b In article number 2103360, Denis Y. W. Yu and co-workers report the development of an all-fluorinated electrolyte which enables highly reversible PF6 SP - sp and Li SP + sp storage towards high performance dual-ion batteries (DIBs). [Extracted from the article]