Porous polymer monolithic columns with gold nanoparticles as an intermediate ligand for the separation of proteins in reverse phase-ion exchange mixed mode

Peer reviewe

The electrochemical behavior of poly 1-pyrenemethyl methacrylate binder and its effect on the interfacial chemistry of a silicon electrode

The physico-chemical properties of poly (1-pyrenemethyl methacrylate) (PPy) are presented with respect to its use as a binder in a Si composite anode for Li-ion batteries. PPy thin-films on Si(100) wafer and Cu model electrodes are shown to exhibit superior adhesion as compared to conventional polyvinylidene difluoride (PVdF) binder. Electrochemical testing of the model bi-layer PPy/Si(100) electrodes in a standard organic carbonate electrolyte reveal higher electrolyte reduction current and an overall irreversible cathodic charge consumption during initial cycling versus the uncoated Si electrode. The PPy thin-film is also shown to impede lithiation of the underlying Si. XAS, AFM, TGA and ATR-FTIR analysis indicated that PPy binder is both chemically and electrochemically stable in the cycling potential range however significant swelling is observed due to a selective uptake of diethyl carbonate (DEC) from the electrolyte. The increased concentration of DEC and depletion of ethylene carbonate (EC) at the Si/PPy interface leads to continuous decomposition of the electrolyte and results in non-passivating behavior of the Si(100)/PPy electrode as compared to pristine silicon. Consequently, PPy binder improves the mechanical integrity of composite Si anodes but it influences mass transport at the Si(100)/PPy interface and alters electrochemical response of silicon during cycling in an adverse manner

Improving the Cycling Performance of High-Voltage NMC111 || Graphite Lithium Ion Cells By an Effective Urea-Based Electrolyte Additive

In order to further increase the energy density of lithium ion batteries (LIBs), it is of utmost importance to develop advanced electrode materials in combination with suitable electrolytes, which deliver either higher capacities and/or can be operated at high cell voltage with sufficient cycling stability. Here, we introduce (1H-imidazol-1-yl)(morpholino)methanone (MUI) as a cathode electrolyte interphase (CEI) forming electrolyte additive for LiNi1/3Co1/3Mn1/3O2 (NMC111) || graphite cells operated at high cell voltage of up to 4.6 V. The addition of MUI to the carbonate-based reference electrolyte leads to a superior cycling stability in comparison to those with the pure reference electrolyte. The working mechanism of MUI is comprehensively elucidated with various ex situ analytical techniques. A reduction of MUI at the graphite anode is observed starting at a potential of ≈0.9 V vs. Li/Li+, resulting in a slightly higher kinetic impairment of lithium ion intercalation/deintercalation into/from graphite. To prevent the unfavorable reduction of MUI at the graphite anode, Li4Ti5O12 (LTO)-based composite anodes are also used to analyze the function of the additive at the cathode surface. We can clearly confirm that a protective film at the cathode surface is formed, helping to suppress parasitic side reactions at the cathode/electrolyte interface during long-term cycling