• Energy Research

Increasing energy demand calls for high‐performance lithium‐ion batteries with good low‐temperature resilience. Conventional intercalation cathodes pose problems such as sluggish interfacial Li‐ion transportation and slow diffusion in bulk electrode at low temperature, hindering their application in cold environment. Prussian blue analogues (PBA) with open framework structure provide viable fast kinetics for low‐temperature operation. Herein, a Mn‐based PBA (MnHCF@CNT composite) is synthesized and forms a unique necklace‐like conductive network by nucleating MnHCF nanoparticles on carbon nanotubes (CNT). Such features endow it with surface‐controlled intercalation pseudocapacitive behavior and high diffusion coefficient of Li+, which shows a high capacity of 103 mAh g−1 at the rate of 20C. Moreover, interfacial pseudocapacitance and fast bulk Li+ diffusion help realize excellent low‐temperature performance, which obtains high capacity of 117 mAh g−1 (corresponding to a capacity retention of 73%) under −40 °C and keeps 52% of its capacity at −70 °C. Full cell based on MnHCF@CNT cathode and Nb2O5 anode can exhibit 57% of its capacity at −40 °C. This research takes a further step toward developing cathode material at low temperature and provides feasible design for battery under subzero environment.

Lithium-ion capacitors (LICs) have been considered as an advanced energy storage system owing to their high energy and power densities. However, their application in a wide temperature range is still a great challenge due to the reduced ionic conductivity of the electrolyte and the poor electric conductivity of the battery-type transition metal oxide electrodes. Herein, an all-climate LIC is well-fabricated with TiNb2O7@expanded graphite as the anode and activated carbon as the cathode in an optimized electrolyte, which can be operated within a wide temperature range from -60 to +55 °C. Benefitting from the synergetic effect of the improved electrode and electrolyte, the LIC exhibits an outstanding energy density of 119 W h kg-1 and a power density of 5110 W kg-1 based on the total mass of both negative and positive electrodes. Moreover, it can deliver a capacity retention of as high as 42% at -60 °C and function at a superior rate capability at a high temperature of +55 °C, which exhibits an all-climate feature and the potential for wide applications under some extreme conditions.

A hybrid electrolyte lithium–air battery, in which a lithium-anode in a non-aqueous electrolyte and an air catalytic cathode in an aqueous electrolyte solution were separated by a ceramic LISICON film, has been investigated in our previous work. In the present work, a capacitor electrode was put in the non-aqueous electrolyte solution as an additional cathode in parallel with the air catalytic cathode. The proposed lithium–air batteries with an additional capacitor cathode can successfully unite capacitor character and lithium–air battery character in one device which is now nominated as a “lithium–air capacitor–battery based on a hybrid electrolyte”. When high power is needed, the capacitor cathode would play the main role of peak power output; when high energy is demanded, the air catalytic cathode would display its high energy character. The adjustability of power output and energy output demonstrate that the proposed lithium–air capacitor–battery should be a promising power system for future electric vehicles.

Zn-organic batteries are attracting extensive attention, but their energy density is limited by the low capacity (<400 mAh g-1) and potential (<1 V vs Zn/Zn2+) of organic cathodes. Herein, we propose a long-life and high-rate Zn-organic battery that includes a poly(1,5-naphthalenediamine) cathode and a Zn anode in an alkaline electrolyte, where the cathode reaction is based on the coordination reaction between K+ and the C═N group (i.e., C═N/C-N-K conversion). Interestingly, we find that the discharged Zn-organic battery can recover to its initial state quickly with the presence of O2, and the theoretical calculation demonstrates that the K-N bond in the discharged cathode can be easily broken by O2 via redox reaction. Accordingly, we design a chemically self-charging aqueous Zn-organic battery. Benefiting from the excellent self-rechargeability, the organic cathode exhibits an accumulated capacity of 16264 mAh g-1, which enables the Zn-organic battery to show a record high energy density of 625.5 Wh kg-1.

Abstract For the first time, the proton-conducting composite phosphotungstic acid PTA/Al 2 (SO 4 ) 3 ·18H 2 O was used as the electrolyte of symmetric supercapacitor based on PANI. The optimum weight ratio of PTA/Al 2 (SO 4 ) 3 ·18H 2 O for using in this supercapacitor was also reported. Electrochemical tests prove that the supercapacitor using this kind of composite as electrolyte has high capacitance performance. Its capacitance is as high as 240 F/g at 6 mA. It was more important that it has long cycle life. After 1000 cycles, the attenuation of the capacitance is less than 10% and the coulombic efficiency is still greater than 96%.

Lithium-metal batteries (LMBs) are the focus of upcoming energy storage systems with extremely high-energy density. However, the leakage of liquid electrolyte and the uncontrollable dendritic Li growth on the surface of the Li anode lead to their low reversibility and safety risks. Herein, we propose a stable quasi-solid LMB with in situ gelation of liquid electrolyte and an in-built fluorinated solid electrolyte interface (SEI) on the Li anode. The gel polymer electrolyte (GPE) is readily constructed via cationic polymerization between lithium hexafluorophosphate and ether electrolyte. The fluorine-containing additive, fluoroethylene carbonate (FEC), plays a crucial role in the building of a dense SEI with fast interfacial charge transport. The ex situ spectroscopic characterizations suggest that the enhanced LiF species in the SEI with the addition of FEC and the in situ optical microscopy reveal the inhibited dendritic Li growth. Moreover, GPE@FEC exhibits a high oxidative stability beyond 5.0 V (vs Li/Li+). The significantly improved Li plating/stripping efficiency (400 cycles, 98.7%) is presented for the Li∥Cu cells equipped with GPE@FEC. Decent cycling stability is also available for the cells with the LiFePO4 cathode, reflecting the feasibility of GPE@FEC for practical LMBs with enhanced stability and safety.

Correlations between the temperature-responsive solvation structure, interfacial chemistry and performance of graphite anodes are revealed to understand the structure–property relationships, providing insights into designing temperature-adaptative batteries.

The flexible utilization of renewables for power-to-fuel and/or power-to-power is enabled by the decoupled amphoteric water electrolysis and Mn–Zn battery.