We reproducibly quantify water content in different SPE systems through the various processing/drying conditions and we tie the residual amounts of water to heightened ionic conductivities. Moreover, we emphasise on...

Substituting flammable liquid electrolytes with solid polymer electrolytes (SPEs) presents a serious challenge in improving the safety of lithium-ion batteries. Even though SPEs are a safer choice, their ionic transport properties are still lower than those of their liquid counterparts (<10 −4 S•cm −1 at room temperature). Here, we report the preparation of a blend of polymers used as SPEs in lithium-ion batteries. Composed of an elastomer, hydrogenated nitrile butadiene rubber (HNBR), and poly(ethylene oxide) (PEO), this blend combines the high conductivity of PEO and the stable properties of HNBR and shows better flexibility than a pristine PEO SPE. It is worth noting that the addition of HNBR, coupled with the intrinsic LiTFSI salt concentration, also reduces the crystallinity and melting temperature of typical PEO-LiTFSI SPEs; this also explains the higher ionic conductivity at low temperature (1.18 × 10 −4 S•cm −1 at 40 °C). Given these initial results, we may conclude that this polymer blend is a promising candidate as an SPE for all solid-state lithium-ion batteries.

Polymer blends have emerged as promising candidates for solid polymer electrolytes (SPEs) in lithium batteries as dry blending polymers allow the benefits of each polymer to be easily combined. However, mixing polymers with different ionic transport properties can complicate the understanding of ion transport mechanisms in the blended material. Indeed, in polymer blends, the contribution of each component to ionic transport differs considerably. This paper presents a systematic study of the salt dissociation ability of polar functional groups in various polymer blends. The blends presented here were obtained through dry processing, which allows the effect of solvents on salt/polymer interactions to be neglected. The studied polymers, which are commonly used to produce SPEs, were selected based on their polar functional groups: PEO (ether), PCL (ester), PPC (carbonate), PVA (alcohol), HNBR (nitrile), and PVP (amide). Given the combined EDX, 7 Li NMR, and FTIR results, a ranking of the lithium salt solvating ability of these polymers as a function of their polar functional groups has been made. This study also provides valuable information that contributes to increase comprehension of ionic transport in SPEs.

Demand for flexible energy storage devices is rapidly increasing due to the development of new wearable and flexible electronics. These developments require improved integration of energy storage devices to meet the design specifications of these products. Polymer hydrogels are an alternative class of flexible electrolytes that can be used in power source systems. Herein, we present a new sustainable hydrogel electrolyte material made with apple pectin. Using an easy solution casting approach, a bio-based hydrogel was formed via pectin gelation. The resultant hydrogel was made with environmentally benign compounds including water, zinc and/or lithium sulfate salt, and a bio-based polymer. This hydrogel electrolyte exhibits ambient temperature ionic conductivities that are similar to those found in aqueous liquid electrolytes (∼5 × 10 −2 S cm −1 ), depending on electrolyte hydration. Its wide thermal stability window enables the electrolyte to be used at both low temperatures (−20 °C) and intermediate temperatures (50 °C), without significant changes in ionic conductivity (>10 −3 S cm −1 ). By proposing an energy-oriented solution using one of the food industry's major waste materials, we report a novel approach to processing a bio-based polymer for energy storage purposes.