Comparisons on other thermal and electrochemical properties of the two types of PEMs are presented in Chapter IV.Tags: Using A Footnote In An EssayEssay Writing Help UkConstitutional Law Essay Exam QuestionsDbq Essay Cold War FearsExample Of A Vision Statement For A Business PlanEssay About Patriotism Of NepalTribute Essay To MomMethods Section Of A Research Paper
In pursuit of safer and more flexible solid-state lithium ion batteries, solid polymer electrolytes have emerged as a promising candidate.
The present dissertation entails exploration of solid plasticized, photopolymerized (i.e.
Lithium bis(trifluoromethanesulfonyl)imide (Li TFSI) was incorporated as a source of lithium ions, while a solid plasticizer succinonitrile (SCN) and a liquid plasticizer tetraethylene glycol dimethyl ether (TEGDME) were incorporated in the respective systems.
The important role of plasticizer on the enhancement of ionic conductivity (σ) to the superionic conductive level (10 S/cm) was revealed in both systems.
Interestingly, improved ionic conductivity was achieved simultaneously.
The dual improvement may be attributed to the less chemical crosslinked points and the more flexible chain motion in the looser network of PEGDA6000-PEM relative to its PEGDA700 counterpart.Phase diagram approach was adopted to guide the fabrication of two types of plasticized PEMs.Prepolymer poly (ethylene glycol) diacrylate (PEGDA) was used as a matrix for building an ionic conductive and mechanically sturdy network.Subsequently, high thermal stability and electrochemical stability of both types of PEMs, as well as the satisfactory room temperature charge/discharge cycling performance of PEM containing lithium ion half-cells were observed.The pertinent information is documented in Chapter VI.In this dissertation, we demonstrated that the two factors, namely tethered chain/dynamic and tortuosity/structural effects can be decoupled by preparing polymer membranes with controlled crystal orientation and measuring the in-plane and through-plane conductivity of the orientated membrane.Moderate conductivity anisotropy as a result of PEO lamellar orientation was first observed in a solution cast PEO SPE.Upon SCN incorporation, these two peaks merged into one that was further suppressed below the T of the pure network, whereas σ improved to the superionic conductor level.The role of SCN on the σ enhancement as both plasticizer for the polymer network and ionizer for the salt is discussed in Chapter V.It is worth noting that photopolymerization induced crystallization (PIC) occurred during UV-curing in the SCN-rich region of the ternary PEGDA/Li TFSI/SCN ternary mixtures.The PEM thus formed contained a plastic crystal phase, which showed lower σ relative to their amorphous PEGDA/Li TFSI/TEGDME counterpart.