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Spinel lithium manganate cathode material suffer from manganese dissolution at high temperature, which is the main culprit of the poor storage and cycling performance. The purpose of this study was to inhibit the manganese dissolution and improve lithium manganate s high temperature performance. The strategy is to coat anti-perovskite solid electrolyte(Li3OCl) on the surface of lithium manganate as an artificial solid electrolyte interphase to isolate lithium manganate from the electrolyte, thus inhibiting the dissolution of manganese. The results show that the ionic conductivity of the anti-perovskite electrolyte coating was as high as 1.12x10-4 S/cm. Inductively coupled plasma results show that the manganese dissolution of lithium manganate cathode materials coated with anti-perovskites is significantly reduced at high temperature compared with that of the uncoated samples. The electrochemical performance of the assembled lithium manganate/lithium metal coin and pouch cells were significantly improved when coated with anti-perovskite electrolyte. The assembled pouch cell displayed an energy density of 297 Wh/kg and a capacity retention rate of 90.2% after 500 cycles at 1C. Therefore, the coating of Li3OCl artificial solid electrolyte interphase can effectively improve the high temperature electrochemical performance of lithium permanganate anode materials. [ABSTRACT FROM AUTHOR]

Ionic porous organic polymer (i-POP) is an emerging class of organic porous polyelectrolytes featuring ionized backbones or side groups on the skeletons. i-POPs are highly designable exhibiting large specific surface areas and intrinsic nanopores. Their physicochemical properties and functionality can be skillfully regulated by varying ionized building blocks. Compared with neutral porous organic polymers, i-POPs possess controllable ionic sites and high charge density, broadening the application ranges of porous organic polymers. Meanwhile, their applicability can be strengthened by the inherent association between pore confinement, skeleton function, and abundant ionic sites. The compositions, structures, and synthetic methods of amorphous i-POPs have been significantly explored in recent years. Tremendous studies have demonstrated that i-POPs are promising for various advanced applications including adsorption/separation, sensing, catalysis and so on. [ABSTRACT FROM AUTHOR]

Li-O² batteries have ultra-high theoretical energy density and they are promising to replace commercial Li-ion batteries in the future. Compared with liquid electrolytes, polymer electrolytes have the advantages of non-flammability and higher electrochemical and thermal stability. Polymer electrolytes containing cerium bromide (CeBr3) additives were prepared, which greatly improved the reliability and stability of Li-O² batteries. Poly(vinylidene fluoride-cohexafluopropylene) (PVDF-HFP) based polymer electrolyte containing CeBr3 was prepared by solution casting method to improve its stability in Li-O² battery. The morphology and composition of the electrode and electrolyte after cycling of Li-O² battery were characterized by Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS) and Fourier Transform Infrared Spectroscopy (FT-IR). The electrochemical performance of lithium-oxygen battery was tested by electrochemical workstation and battery test system to study the enhancement effect of CeBr3 on the stability of polymer electrolyte. The experimental results demonstrate the bifunctional effect of CeBr3 in PVDF-HFP electrolyte by trapping superoxide radicals and reducing the charging overpotential. The ionic conductivity of the electrolyte at 25 ℃ is 5.87×10−4 S/cm. At a current density of 500 mA/g and specific capacity of 1 000 mA·h/g, the Li-O² battery with traditional PVDF-HFP polymer electrolyte drops the voltage below 2 V after 47 cycles, while the Li-O² battery with PVDF-HFP-CeBr3 polymer electrolyte can reach up to 112 cycles. [ABSTRACT FROM AUTHOR]

The development of nickel-rich and low-cobalt cathode materials is currently an effective way to improve the energy density and reduce the cost of lithium-ion batteries. However, as Ni content increases, Ni-rich layered oxides have some problems, such as difficult precursor synthesis, structural instability, and high interfacial activity, which hinder the promotion of Ni-rich layered oxide cathode materials. In this paper, a structurally stable LiNi0.8 Mn0.1 Co0.1 O2 (NCM811) cathode material was prepared by an optimized co-precipitation method, while a fast ionic conductor Li1.5 Y0.5 Zr1.5 (PO4)3 coating was uniformly wrapped on the surface of NCM811 material to overcome the difficulties of interfacial structural instability and electrolyte corrosion. At a high cut-off voltage of 4.5 V, the discharge specific capacity of the modified sample is 214.2 mAh⋅g-1 at 0.2 C and up to 158.8 mAh ⋅ g-1 at 10 C, which is much higher than the 203.7 mAh⋅g-1 (0.2 C) and 82.7 mAh ⋅ g-1 (10 C) of the original sample. Meanwhile, the capacity retention rate of the modified sample after 200 cycles of 1 C at 4.3 V is as high as 84.7%, which is higher than that of the original sample (61.94%). [ABSTRACT FROM AUTHOR]

Solid polymer electrolyte (SPE) has attracted more and more attention due to its unique safety performance. Here, we prepared a PEO-based high-performance solid-state polymer electrolyte with a novel poly(ionic liquid) (PIL)/ionic liquid (IL) blend-modified poly(ethylene oxide). The crystal structure and thermal stability of the samples were investigated by X-ray diffraction (XRD) and thermogravimetric (TG) methods. The results showed that the introduction of PIL/IL significantly reduced the crystallinity and exhibited high thermal stability (320 ℃). The electrochemical properties of solid polymer electrolytes were investigated by electrochemical impedance (EIS), linear sweep voltammetry (LSV). The results showed that the reduction of crystallinity significantly improved the ionic conductivity (2.27×10-4 S/cm, 40 °C) and lithium-ion transference number (0.3, 40 °C). At the same time, the electrochemical window is improved due to the substitution of the proton hydrogen on the C(2) position of the imidazole ring by an alkyl group. By assembling the LiFePO4/Li cell for charge and discharge tests, it was found that the stable discharge capacity was as high as 150 mAh/g. The discharge capacity remained unchanged after 100 cycles, and the Coulomb efficiency remained above 99%, showing high capacity and cycle stability. [ABSTRACT FROM AUTHOR]

As a lightweight energy system, lithium ion batteries are used in different industries and fields. The electrolyte acts as a channel for ion transmission in the battery. Polymer materials are applied as electrolyte since they have the advantages of high safety, high thermal stability and high mechanical strength. However, polymer will crack in certain external environments. Thus, some researchers proposed to prepare self-healing materials and applied them to electrolyte in lithium ion battery. This work is dedicated to solve the problem that the polymer electrolyte is susceptible to mechanical damage. The preparation method of 2-ureido-4-[1H]-pyrimidinone (Upy) unit which contains the quadruple hydrogen bonds was proposed. And grafted Upy on the polyvinyl alcohol (PVA) polymer matrix was performed to prepare a self-healing electrolyte material. The chemical structure, thermal stability, self-healing ability and electrochemical performance of PVAUpy membrane were studied. The results showed that PVA-Upy material was successfully prepared by this method and proved by FT-IR and 1H-NMR measurement. PVA-Upy material showed good thermal stability and mechanical strength, and had a self-healing efficiency of 90.20% in tensile strength at 70 ℃. As for electrolyte, it had an electrochemical window of 5 V and its highest ion conductivity was 2.06×10−3 S/cm. Being assembled as LiFePO4/PVA-Upy/Li cell, it showed good cycle stability which suggested the application prospect in lithium ion batteries. [ABSTRACT FROM AUTHOR]

A photo-polymerization synthesis process without organic solvent was used. Polyethylene glycol methacrylate ( PEG475 ) was used as the matrix, N, N dimethyl acrylamide ( DMAA) was used as the crosslinking agent, and the plasticizer succinonitrile (SN)was introduced, a new all-solid polymer electrolyte ( PEG475-DMAA) was prepared and its electrochemical performance was tested. The results showed that when the addition amount of SN was 10% (mass fraction), the ionic conductivity of the electrolyte system was the largest, about 4 x10-5 S/cm, which was increased by three orders of magnitude relative to the polyoxyethylene system. The electrochemical stability window was above 5. 0 V, which satisfied the voltage stability requirements of the currently-used electrolyte system. The electrolyte had good thermal stability in the range of 270 °C. The lithium ion battery assembled by the electrolyte membrane had a low initial capacity. There was still a big gap with commercial lithium-ion batteries. In the future, it is necessary to further improve the ionic conductivity of the electrolyte membrane and improve the electrochemical cycle performance. [ABSTRACT FROM AUTHOR]