Large-Scale Fabrication of Boron Nitride Nanosheets and Their Utilization in Polymeric Composites with Improved Thermal and Mechanical Properties

More than a decade of research in the field of thermal, motion, vibration and electromagnetic radiation energy harvesting has yielded increasing power output and smaller embodiments. Power management circuits for rectification and DC-DC conversion are becoming able to efficiently convert the power from these energy harvesters. This paper summarizes recent energy harvesting results and their power management circuits.

Micropower energy harvesting

Solid-state batteries have been attracting wide attention for next generation energy storage devices due to the probability to realize higher energy density and superior safety performance compared with the state-of-the-art lithium ion batteries. However, there are still intimidating challenges for developing low cost and industrially scalable solid-state batteries with high energy density and stable cycling life for large-scale energy storage and electric vehicle applications. This review presents an overview on the scientific challenges, fundamental mechanisms, and design strategies for solid-state batteries, specifically focusing on the stability issues of solid-state electrolytes and the associated interfaces with both cathode and anode electrodes. First, we give a brief overview on the history of solid-state battery technologies, followed by introduction and discussion on different types of solid-state electrolytes. Then, the associated stability issues, from phenomena to fundamental understandings, are intensively discussed, including chemical, electrochemical, mechanical, and thermal stability issues; effective optimization strategies are also summarized. State-of-the-art characterization techniques and in situ and operando measurement methods deployed and developed to study the aforementioned issues are summarized as well. Following the obtained insights, perspectives are given in the end on how to design practically accessible solid-state batteries in the future.

Approaching Practically Accessible Solid-State Batteries: Stability Issues Related to Solid Electrolytes and Interfaces

Easy processing and flexibility of polymer electrolytes make them very promising in developing all-solid-state lithium batteries. However, their low room-temperature conductivity and poor mechanical and thermal properties still hinder their applications. Here, we use Li6.75La3Zr1.75Ta0.25O12 (LLZTO) ceramics to trigger structural modification of poly(vinylidene fluoride) (PVDF) polymer electrolyte. By combining experiments and first-principle calculations, we find that La atom of LLZTO could complex with the N atom and C═O group of solvent molecules such as N,N-dimethylformamide along with electrons enriching at the N atom, which behaves like a Lewis base and induces the chemical dehydrofluorination of the PVDF skeleton. Partially modified PVDF chains activate the interactions between the PVDF matrix, lithium salt, and LLZTO fillers, hence leading to significantly improved performance of the flexible electrolyte membrane (e.g., a high ionic conductivity of about 5 × 10–4 S cm–1 at 25 °C, high mechanical s...

Synergistic Coupling between Li6.75La3Zr1.75Ta0.25O12 and Poly(vinylidene fluoride) Induces High Ionic Conductivity, Mechanical Strength, and Thermal Stability of Solid Composite Electrolytes

A review of lithium and non-lithium based solid state batteries

Composite polymer electrolytes based on poly(ethylene glycol) (PEG), magnesium acetate [Mg(CH3COO)2], and x wt% of cerium oxide (CeO2) ceramic fillers (where x = 0, 5, 10, 15 and 20, respectively) have been prepared using solution casting technique. X-ray diffraction patterns of PEG–Mg(CH3COO)2 with CeO
 2
 ceramic filler indicated the decrease in the degree of crystallinity with increasing concentration of the filler. DSC measurements of PEG–Mg(CH3COO)2–CeO2 composite polymer electrolyte system showed that the melting temperature is shifted towards the lower temperature with increase of the filler concentration. The conductivity results indicate that the incorporation of ceramic filler up to a certain concentration (i.e. 15 wt%) increases the ionic conductivity and upon further addition the conductivity decreases. The transference number data indicated the dominance of ion-type charge transport in these specimens. Using this (PEG–Mg(CH3COO)2–CeO2) (85-15-15) electrolyte, solid-state electrochemical cell was fabricated and their discharge profiles were studied under a constant load of 100 kΩ.

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Preparation and characterization of PEG–Mg(CH 3 COO) 2 –CeO 2 composite polymer electrolytes for battery application

Composite polymer electrolyte films consisting of polyethylene glycol (PEG), Mg(CH3COO)2 and Al2O3 particles have been prepared by solution casting technique. The X-ray diffraction patterns of PEG-Mg(CH3COO)2 with Al2O3 ceramic filler, indicates the decrease in the degree of crystallinity with increasing concentration of the filler. The role of ceramic phase is to reduce the melting temperature which is ascertained from the DSC. The effect of ceramic filler on the conductivity of the polymer electrolyte was studied. The maximum ionic conductivity has been observed for 10 wt% of Al2O3 at room temperature (303 K). The transference number data indicated the dominance of ion-type charge transport in these composite polymer electrolytes. Using this (PEG-Mg(CH3COO)2-Al2O3) (85–15–10) electrolyte, solid-state electrochemical cell was fabricated and their discharge profiles were studied under a constant load of 100 kΩ. Several cell profiles associated with this cell were evaluated and are reported. Copyright © 2013 VBRI press.

Effect of Al2O3 ceramic filler on PEG-based composite polymer electrolytes for magnesium batteries

Adding organic–inorganic hybrid nanoparticles is a potential way to enhance room temperature ionic conductivity and mechanical strength of solid polymer electrolytes (SPEs). In this work, a new nanocomposite solid polymer electrolyte (NSPE) based on poly(ethylene oxide)–lithium bis(trifluoromethane sulfonyl) imide (PEO12–LiTFSI) incorporating polyhedral oligomeric silsesquioxane–poly(ethylene glycol) (POSS–PEG(n = 4)) hybrid nanoparticles has been prepared and reported the effect of POSS–PEG(n = 4) hybrid nanoparticles on thermal, mechanical, and electrical properties of (PEO12–LiTFSI) SPE. Results from X-ray diffraction and differential scanning calorimetry studies indicated that the conductivity increase was due to the decrease in crystallinity upon the addition of lithium salt and POSS–PEG hybrid nanoparticles into the SPE system. The mechanical properties of PEO12–LiTFSI SPE tended to increase with the addition of POSS–PEG(n = 4) nanoparticles up to 10 wt% and decreased afterwards. The NSPEs having solid state show quite high ionic conductivity (1.45 × 10−4 S/cm at 30°C), which is about 7.44 times of magnitude larger than that of the matrix polymer (PEO12–LiTFSI) electrolyte (1.95 × 10−5 S/cm at 30°C).

Effect of Organic–Inorganic Hybrid Nanoparticles (POSS–PEG(n = 4)) on Thermal, Mechanical, and Electrical Properties of PEO‐Based Solid Polymer Electrolytes

Composite polymer electrolyte (CPE) materials are very attractive for components of batteries and optoelectronic devices. Polyethylene glycol–magnesium nitrate polymer electrolytes and their composites were prepared by using addition of different weight percentage of titanium dioxide (TiO2) and cerium oxide ceramic fillers. Several experimental techniques, such as composition-dependence conductivity, temperature-dependence conductivity, and transport number measurements, have been employed to characterize these CPEs. The magnitude of conductivity increased with increase in the concentration of the ceramic fillers and temperature. The highest ionic conductivity achieved was 1.06 × 10−4 S/cm for the sample prepared with 10 wt% of TiO2 at room temperature. The charge transport in the present CPEs was obtained using Wagner’s polarization technique, which demonstrated that the charge transport was mainly due to ions. Using these polymer electrolytes, solid-state electrochemical cells were fabricated and their ...

Anji Reddy Polu

Papers

Preparation and characterization of PEG–Mg(CH 3 COO) 2 –CeO 2 composite polymer electrolytes for battery application

Effect of Al2O3 ceramic filler on PEG-based composite polymer electrolytes for magnesium batteries

Effect of Organic–Inorganic Hybrid Nanoparticles (POSS–PEG(n = 4)) on Thermal, Mechanical, and Electrical Properties of PEO‐Based Solid Polymer Electrolytes

Effect of ceramic fillers on polyethylene glycol-based solid polymer electrolytes for solid-state magnesium batteries

Mg 2 + -ion conducting poly(ethylene glycol)-TiO 2 composite polymer electrolytes for solid-state batteries