Atomistic modelling approaches to understanding the interfaces of ionic liquid electrolytes for batteries and electrochemical devices

Atomistic modelling approaches to understanding the interfaces of ionic liquid electrolytes for batteries and electrochemical device

Correction: elucidation of transport mechanism and enhanced alkali ion transference numbers in mixed alkali metal-organic ionic molten salts

Correction for 'Elucidation of transport mechanism and enhanced alkali ion transference numbers in mixed alkali metal-organic ionic molten salts' by Fangfang Chen et al., Phys. Chem. Chem. Phys., 2016, 18, 19336-19344

Cationic polymer-in-salt electrolytes for fast metal ion conduction and solid-state battery applications

Cationic polymer-in-salt electrolytes for fast metal ion conduction and solid-state battery application

Ionic Liquid and Polymer‐Based Electrolytes for Sodium Battery Applications

Ionic Liquid and Polymer‐Based Electrolytes for Sodium Battery Application

Polar Organic Cations at Electrified Metal with Superconcentrated Ionic Liquid Electrolyte and Implications for Sodium Metal Batteries

Understanding the potential-induced changes across the electrode/electrolyte interface, the so-called electric double layer (EDL), is essential to adjust the working properties of energy-storage devices. Electrolytes with a high molar ratio of metal salt to solvent (1:1 salt:solvent), e.g., superconcentrated ionic liquids (ILs), enable uniform metal deposition, formation of stable solid-electrolyte interphase (SEI), and higher redox stability, which make them attractive for battery applications. However, the presence of an organic IL cation and its interactions with metal salt complexes can significantly impact the mechanism of charge transfer at an electrode compared with conventional ether/ester-based electrolytes. The competition between IL and metal cations to enter the electrified interface affects interfacial chemistry, a key determinant of metal deposition potential and the nature of the SEI. This, in turn, is also affected by IL cation and anion chemistries, which are not yet fully understood. This letter demonstrates that the polarity of an organic IL cation, which is expressed through its dipole moment (μ), and its redox stability can serve as a predictive descriptor for EDL structure in superconcentrated IL electrolytes and the implications for charge transfer. We showed that, in the family of pyrrolidinium cations, a less polar organic cation with a small μ, e.g. N-methyl-N-ethylpyrrolidinium [C2mpyr]+, packs tighter and in a greater number at a negatively charged electrode/electrolyte interface in comparison to more polar IL cations with greater μ, e.g. N-methyl-N-propylpyrrolidinium [C3mpyr]+ and N-methyl-N-methoxymethylpyrrolidinium [C2O1mpyr]+. This IL cation-rich interface results in a greater overpotential for Na deposition, whereas the nature of the SEI and sodium anode cycling behavior correlate with both the dipole moment and the reductive stability of the IL cation

Probing interactions and dynamics in ether-functionalized ionic liquid electrolytes using 17O NMR spectroscopy and molecular modelling

Probing interactions and dynamics in ether-functionalized ionic liquid electrolytes using 17O NMR spectroscopy and molecular modellin

Ammonium-Based Plastic Crystals as Solid-State Electrolytes for Lithium and Sodium Batteries

Ammonium-Based Plastic Crystals as Solid-State Electrolytes for Lithium and Sodium Batteries</p

Effect of cetrimonium carrier micelles on bacterial membranes and extracellular DNA, an in silico study

AbstractMicroorganisms do not live as dispersed single cells but rather they form aggregates with extracellular polymeric substances at interfaces. Biofilms are considered efficient life forms because they shield bacteria from biocides and collect dilute nutrients. This is a big concern in industry since the microorganisms can colonize a wide range of surfaces, accelerating material deterioration, colonizing medical devices, contaminating ultrapure drinking water, increasing energy costs and creating focus of infection. Conventional biocides that target a specific component of the bacteria are not effective in the presence of biofilms. Efficient biofilm inhibitors are based on a multitarget approach interacting with the bacteria and the biofilm matrix. Their rationale design requires a thorough understanding of inhibitory mechanisms that are still largely lacking today. Herein we uncover via molecular modelling the inhibition mechanism of cetrimonium 4-OH cinnamate (CTA-4OHcinn). Simulations show that CTA-4OH micelles can disrupt symmetric and asymmetric bilayers, representative of inner and outer bacterial membranes, following three stages: adsorption, assimilation, and defect formation. The main driving force for micellar attack is electrostatic interactions. In addition to disrupting the bilayers, the micelles work as carriers facilitating the trapping of 4OH cinnamate anions within the bilayer upper leaflet and overcoming electrostatic repulsion. The micelles also interact with extracellular DNA (e-DNA), which is one of the main components of biofilms. It is observed that CTA-4OHcinn forms spherical micelles on the DNA backbone; which hinders their ability to pack. This is demonstrated by modelling the DNA along the hbb histone-like protein, showing that in the presence of CTA-4OHcinn, DNA does not pack properly around hbb. The abilities of CTA-4OHcinn to cause cell death through membrane disruption and to disperse a mature, multi-species biofilm are also confirmed experimentally

A reflection on polymer electrolytes for solid-state lithium metal batteries

Before the debut of lithium-ion batteries (LIBs) in the commodity market, solid-state lithium metal batteries (SSLMBs) were considered promising high-energy electrochemical energy storage systems before being almost abandoned in the late 1980s because of safety concerns. However, after three decades of development, LIB technologies are now approaching their energy content and safety limits imposed by the rocking chair chemistry. These aspects are prompting the revival of research activities in SSLMB technologies at both academic and industrial levels. In this perspective article, we present a personal reflection on solid polymer electrolytes (SPEs), spanning from early development to their implementation in SSLMBs, highlighting key milestones. In particular, we discuss the SPEs’ characteristics taking into account the concept of coupled and decoupled SPEs proposed by C. Austen Angell in the early 1990s. Possible remedies to improve the physicochemical and electrochemical properties of SPEs are also examined. With this article, we also aim to highlight the missing blocks in building ideal SSLMBs and stimulate research towards innovative electrolyte materials for future rechargeable high-energy batteries

The impact of electrode conductivity on electrolyte interfacial structuring and its implications on the Na^0/+ electrochemical performance

Molecular and ionic assemblies at electrode/liquid electrolyte interfaces, i.e., the electric double layer (EDL), define battery performance by directing the formation of stable interphases. An unstable interphase can hamper metal-cation diffusion, lead to continuous electrolyte consumption, and also promote non-uniform electrochemical processes like dendrite formation. The co-selection of electrolyte chemistry and initial cycling conditions together are generally considered for the design of desirable interphases. At the same time, the dielectric nature of the electrode material is largely ignored, notwithstanding the high unreliability of the assumption that the nature of the EDL and the mechanism of the interphase formation at metallic and semiconductive electrodes are identical. Here we show that the dielectric nature of the charged electrode greatly affects the interfacial metal-anion-solvent composition; therefore, different interphase chemistry will be formed, suggesting different initial cycling conditions need to be established on a case-by-case basis to form the desired interphase. This phenomenon correlates with the metal ion solvation chemistry and the adsorption of species at the electrified electrode due to the competition of van der Waals and coulombic interactions