Alternative electrode fabrication for Lithium-Ion batteries using flame spray Pyrolysis

Alternative Electrode Fabrication for Lithium-Ion Batteries using Flame Spray Pyrolysi

Flame aerosol deposited Li4Ti5O12 layers for flexible, thin film all-solid-state Li-ion batteries

Flexible thin film all-solid-state Li-ion batteries are considered as promising candidates to power a multitude of flexible and miniaturized electronic devices. The production of crystalline battery active materials generally involves high process temperatures above 500 °C. One current challenge in mechanically flexible thin film electrode fabrication is the direct deposition of such crystalline active materials onto temperature sensitive substrates. In the current work we have made a paradigm shift depositing highly pure crystalline Li4Ti5O12nanoparticles onto a flexible polyimide foil in a single step using flame spray pyrolysis technique. The Li4Ti5O12films were mechanically compressed at room temperature to 0.55 μm thin layers, to enhance their adhesion to the substrates, i.e. to increase mechanical stability. The smooth Li4Ti5O12 electrodes were covered with a solid electrolyte and tested against lithium metal electrodes. Stable electrochemical cycling behavior of the battery cells demonstrated the feasibility of the proposed technique for LTO thin film electrode fabrication on temperature sensitive and mechanically flexible polyimide substrates. Fundamental data on possible electrode cyclability upon electrode bending was obtained by successful cycling of LTO flex-TFBs in statically bent condition. This study could initialize a new branch for facile manufacturing of flexible thin film battery cells

Influence of free PCL in PCL/PBA-a copolymers and blends on morphology, thermo-mechanical and shape memory properties

Poly(ε-caprolactone) (PCL) and bisphenol A based polybenzoxazine (PBA-a) blends and copolymers differing in the amount of PCL and bonding mode are reported aiming at studying the role of free PCL. Copolymers containing and lacking free PCL were used to understand the influence of PCLs bonding mode on morphology and mechanical properties. XRD and DSC studies revealed that free PCL in the samples increased the degree of crystallinity in contrast to samples containing similar but bound amounts of PCL. Free PCL tends to phase separate leading to discontinuous phases in the appropriate blends in contrast to smooth surfaces and homogeneous copolymer-like samples as confirmed by AFM and SEM micrographs. Reduced crystallinity due to the absence of free PCL results in a less stabilized network and thereby in a diminished material stiffness. In view of shape memory properties, this study revealed that both a widened network due to covalent PCL incorporation and the existence of free and motile PCL facilitating crystallization are important parameters for the occurrence of shape memory abilities in PCL/PBA-a copolymers

Fabrication and performance of Li4Ti5O12/C Li-ion battery electrodes using combined double flame spray pyrolysis and pressure-based lamination technique

Reduction of lithium-ion battery (LIB) production costs is inevitable to make the use of LIB technology more viable for applications such as electric vehicles or stationary storage. To meet the requirements in today's LIBcost efficiency, our current research focuses on an alternative electrode fabrication method, characterized by a combination of double flame spray pyrolysis and lamination technique (DFSP/lamination). In-situ carbon coatednano-Li4Ti5O12 (LTO/C) was synthesized using versatile DFSP. The as-prepared composite powder was then directly laminated onto a conductive substrate avoiding the use of any solvent or binder for electrode preparation. The influence of lamination pressures on the microstructure and electrochemical performance of the electrodes was also investigated. Enhancements in intrinsic electrical conductivity were found for higher lamination pressures. Capacity retention of highest pressurized DFSP/lamination-prepared electrode was 87.4%after 200 dis-/charge cycles at 1C (vs. Li). In addition, LTO/C material prepared from the double flame spray pyrolysis was also used for fabricating electrodes via doctor blading technique. Laminated electrodes obtained higher specific discharge capacities compared to calendered and non-calendered blade-casted electrodes due to superior microstructural properties. Such a fast and industrially compelling integrative DFSP/lamination tool could be a prosperous, next generation technology for low-cost LIB electrode fabrication

Supervised pelvic floor muscle exercise is more effective than unsupervised pelvic floor muscle exercise at improving urinary incontinence in prostate cancer patients following radical prostatectomy – a systematic review and meta-analysis

Background: Urinary incontinence is one of the most clinically relevant side effects in the treatment of prostate cancer patients. The aim of this systematic review and meta-analysis was to analyze the specific exercise effects of supervised versus unsupervised pelvic floor muscle exercise (PFME) and exercise volume on urinary incontinence status after radical prostatectomy. Methods: A systematic data search was performed for studies published from January 2000 to December 2020 using the following databases: PubMed, Embase, SciSearch, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Database of Abstracts of Reviews and Effects. The review was undertaken according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A random-effects meta-analysis of urinary incontinence remission was performed. The relation between time since surgery and urinary incontinence remission was analyzed using a non-linear dose-response meta-analysis. Results: The meta-analysis included 20 randomized controlled trials involving 2188 men (n = 1105 in intervention groups; n = 1083 in control groups). PFME versus no PFME had a beneficial effect on urinary incontinence remission at 3 months, 3–6 months, and more than 6 months post-surgery, with risk differences ranging from 12 to 25%. These effects were particularly evident for higher volume, supervised PFME in the first 6 months post-surgery. Additional biofeedback therapy appeared to be beneficial but only during the first 3 months post-surgery. Conclusions: There is good evidence that the supervised PFME causes a decrease in short-term urinary incontinence rates. Unsupervised PFME has similar effects as no PFME in postoperative urinary incontinence. PFME programs should be implemented as an early rehabilitative measure to improve postoperative short-term urinary incontinence in patients with prostate cancer.IMPLICATIONS FOR REHABILITATION Prostate cancer, surgery, and urinary incontinence The surgical treatment of prostate cancer often leads to urinary incontinence. Pelvic floor training leads to a significant improvement of this situation. Exercise therapy support is very important in this context and is even more effective than unsupported training

Supervised pelvic floor muscle exercise is more effective than unsupervised pelvic floor muscle exercise at improving urinary incontinence in prostate cancer patients following radical prostatectomy - a systematic review and meta-analysis

Background Urinary incontinence is one of the most clinically relevant side effects in the treatment of prostate cancer patients. The aim of this systematic review and meta-analysis was to analyze the specific exercise effects of supervised versus unsupervised pelvic floor muscle exercise (PFME) and exercise volume on urinary incontinence status after radical prostatectomy. Methods A systematic data search was performed for studies published from January 2000 to December 2020 using the following databases: PubMed, Embase, SciSearch, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Database of Abstracts of Reviews and Effects. The review was undertaken according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A random-effects meta-analysis of urinary incontinence remission was performed. The relation between time since surgery and urinary incontinence remission was analyzed using a non-linear dose-response meta-analysis. Results The meta-analysis included 20 randomized controlled trials involving 2188 men (n = 1105 in intervention groups; n = 1083 in control groups). PFME versus no PFME had a beneficial effect on urinary incontinence remission at 3 months, 3-6 months, and more than 6 months post-surgery, with risk differences ranging from 12 to 25%. These effects were particularly evident for higher volume, supervised PFME in the first 6 months post-surgery. Additional biofeedback therapy appeared to be beneficial but only during the first 3 months post-surgery. Conclusions There is good evidence that the supervised PFME causes a decrease in short-term urinary incontinence rates. Unsupervised PFME has similar effects as no PFME in postoperative urinary incontinence. PFME programs should be implemented as an early rehabilitative measure to improve postoperative short-term urinary incontinence in patients with prostate cancer

Screening Precursor–Solvent Combinations for Li₄Ti₅O₁₂ Energy Storage Material Using Flame Spray Pyrolysis

The development and industrial application of advanced lithium based energy-storage materials are directly related to the innovative production techniques and the usage of inexpensive precursor materials. Flame spray pyrolysis (FSP) is a promising technique that overcomes the challenges in the production processes such as scalability, process control, material versatility, and cost. In the present study, phase pure anode material Li₄Ti₅O₁₂ (LTO) was designed using FSP via extensive systematic screening of lithium and titanium precursors dissolved in five different organic solvents. The effect of precursor and solvent parameters such as chemical reactivity, boiling point, and combustion enthalpy on the particle formation either via gas-to-particle (evaporation/nucleation/growth) or via droplet-to-particle (precipitation/incomplete evaporation) is discussed. The presence of carboxylic acid in the precursor solution resulted in pure (>95 mass %) and homogeneous LTO nanoparticles of size 4–9 nm, attributed to two reasons: (1) stabilization of water sensitive metal alkoxides precursor and (2) formation of volatile carboxylates from lithium nitrate evidenced by attenuated total reflection Fourier transform infrared spectroscopy and single droplet combustion experiments. In contrast, the absence of carboxylic acids resulted in larger inhomogeneous crystalline titanium dioxide (TiO₂) particles with significant reduction of LTO content as low as ∼34 mass %. In-depth particle characterization was performed using X-ray diffraction with Rietveld refinement, thermogravimetric analysis coupled with differential scanning calorimetry and mass spectrometry, gas adsorption, and vibrational spectroscopy. High-resolution transmission electron microscopy of the LTO product revealed excellent quality of the particles obtained at high temperature. In addition, high rate capability and efficient charge reversibility of LTO nanoparticles demonstrate the vast potential of inexpensive gas-phase synthesis for energy-storage materials