Rechargeable batteries are becoming increasingly important for our daily life due to their strong capability of efficiently storing electric energy under chemical form. The replacement of conventional liquid electrolytes with polymer electrolytes (PEs) has been deemed as one of the most viable solutions towards safer and higher energy density electrochemical energy storage systems which are coveted for e-mobility applications (e.g., electric vehicles, EVs). In recent years, the introduction of inorganic materials into PEs has captured escalating interest, aiming at harmonizing advantages from both organic and inorganic phases. In this review, we present the progress and recent advances in PEs containing nano-sized inorganic materials, with due attention paid to the role of inorganic phases on the physical and chemical properties of the electrolytes. The paradigm shift from composite polymer electrolytes (CPEs, obtained by physical blending) to hybrid polymer electrolytes (HPEs, obtained by chemical grafting) is highlighted and the possible improvement and future directions in CPEs and HPEs are discussed.

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High‐voltage lithium polymer cells are considered an attractive technology that could out‐perform commercial lithium‐ion batteries in terms of safety, processability, and energy density. Although significant progress has been achieved in the development of polymer electrolytes for high‐voltage applications (> 4 V), the cell performance containing these materials still encounters certain challenges. One of the major limitations is posed by poor cyclability, which is affected by the low oxidative stability of standard polyether‐based polymer electrolytes. In addition, the high reactivity and structural instability of certain common high‐voltage cathode chemistries further aggravate the challenges. In this review, the oxidative stability of polymer electrolytes is comprehensively discussed, along with the key sources of cell degradation, and provides an overview of the fundamental strategies adopted for enhancing their cyclability. In this regard, a statistical analysis of the cell performance is provided by analyzing 186 publications reported in the last 17 years, to demonstrate the gap between the state‐of‐the‐art and the requirements for high‐energy density cells. Furthermore, the essential characterization techniques employed in prior research investigating the degradation of these systems are discussed to highlight their prospects and limitations. Based on the derived conclusions, new targets and guidelines are proposed for further research.

This work reports the preparation, characterization and test in a single fuel cell of two families of hybrid inorganic-organic proton-conducting membranes, each based on Nafion and a different "core-shell" nanofiller. Nanofillers, based on either a ZrO 2 "core" covered with a HfO 2 "shell" (ZrHf) or a HfO 2 "core" solvated by a "shell" of SiO 2 nanoparticles (SiHf), are considered. The two families of membranes are labelled [Nafion/(ZrHf) x ] and [Nafion/ (SiHf) x ], respectively. The morphology of the nanofillers is investigated with high-resolution transmission electron microscopy (HR-TEM), energy dispersive X-ray spectroscopy (EDX) and electron diffraction (ED) measurements. The mass fractions of nanofiller x used for both families are 0.05, 0.10 or 0.15. The proton exchange capacity (PEC) and the water uptake (WU) of the hybrid membranes are determined. The thermal stability is investigated by high-resolution thermogravimetric measurements (TGA). Each membrane is used in the fabrication of a membrane-electrode assembly (MEA) that is tested in single-cell configuration under operating conditions. The polarization curves are determined by varying the activity of the water vapour (a H2O) and the back pressure of the reagent streams. A coherent model is proposed to correlate the water uptake and proton conduction of the hybrid membranes with the microscopic interactions between the Nafion host polymer and the particles of the different "coreeshell" nanofillers.

Research and development of post lithium ion batteries is attracting considerable attention. While there have been significant advances in understanding the challenges of Li-O2(air) and Li-S batteries, the development of gas separation and ion selective membranes will be crucial in their commercialization due to their potential to separate O2 from air and impede lithium polysulfide dissolution while permitting rapid diffusion of lithium ions. In addition, research leading to novel and highly conductive and selective polymer electrolytes will be essential in overcoming the deficiencies of liquid based electrolytes in both the air and sulfur based battery systems

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Diffusion coefficients are important parameters for the characterization of new electrode materials, but they are also essential for the study of cell aging and as input parameters in battery modeling. In this report, the applicability of the galvanostatic intermittent titration technique (GITT) on commercial cells is studied. A GITT protocol is applied on a set of commercial cells with graphite anodes and various cathode materials. The cell response is then compared with the ones of the individual electrodes, obtained in three-electrode and half-cell configurations. In particular, mostly due to the particular potential profile of graphite, the full cell GITT response corresponds to the anode and cathode response at low and high state of charge, respectively. Therefore, it is possible to estimate the diffusion coefficients of the individual electrodes by a simple experiment on commercial cells, although only in limited ranges of SOC. If the experiments are performed at different temperatures, it is also possible to determine the activation energies of the diffusion coefficients. In conclusion, GITT allows an estimation of the diffusivity data in commercial cells, and can be therefore used as fast analytical tool for the study of aging and for the modeling of lithium-ion batteries.

Unravelling lithium storage mechanism in high performance MnO2@CNT Li-ion battery anode by in situ X-ray synchrotron scattering.