Silicon is a promising anode material for lithium‐ion batteries with its superior capacity. However, the drastic volume changes during lithiation/delithiation cycles hinder the cycling performance, resulting in particle pulverization, conductivity loss, and an unstable electrode–electrolyte interface. Herein, a series of synthetic polymeric binders, poly(acrylic acid‐co‐tetra(ethylene glycol) diacrylate)—featuring a poly(acrylic acid) (PAA) backbone branched via tetra(ethylene glycol) diacrylate (TEGDA)—are developed that edge toward evidencing well‐balanced properties to confront capacity fading in Si‐based electrodes. The incorporation of ether chain not only leads to the branching architecture of the PAA backbone, thus affecting its mechanical properties, but also promotes the conductivity of Li ions. As a result, a synergistic performance improvement is observed in both half and full cells. The best‐performing cell using a branched PAA binder (bPAA) with a feeding molar ratio ([TEGDA]:[acrylic acid(AA)]) of 0.2 results in a 10% increase in initial capacity and a 31% increase in capacity retention over 100 cycles compared to the linear PAA cell. The cross‐sectional microscopic images of the cycled electrodes reveal that bPAA binders can drastically reduce the electrode expansion. This improvement results from the well‐balanced properties of the polymer design, which could guide further development for more advanced binder materials.

Solvating cations help to lift the thermodynamic-kinetic constrain of an anolyte redoxmer by achieving a synergetic improvement of two conflicting properties: a lower redox potential AND a higher stability of the charged radical anion.

A three-component (cross-linked poly­(ionic liquid) (PIL)–ionic liquid (IL)–zeolite), mixed-matrix membrane (MMM) platform based on curable IL prepolymers of controlled length has been developed for separating CO2 from CH4. Solutions of these curable prepolymers demonstrate increased resistance to support penetration compared to comparable solutions of analogous cross-linkable IL monomers. By adjusting the curable IL prepolymer chain length, it is possible to manipulate polymer susceptibility to support penetration, polymer solution gelation time, and gas separation performance in MMMs based on these materials. When a 50 wt % solution of the curable IL prepolymer with a degree of polymerization (x) of 87 was cast on an ultrafiltration support membrane, only 3.7 wt % of the polymer penetrated into the support. As the degree of polymerization of the curable IL prepolymer increases, the CO2/CH4 gas separation performance of the resulting MMM performance also improves. For example, an MMM synthesized using 64 wt % curable IL prepolymer (x = 87), 16 wt % [EMIM]­[Tf2N] as the IL, and 20 wt % SAPO-34 zeolite exhibited a CO2/CH4 selectivity of (42 ± 5) and a CO2 permeability of (47 ± 1) barrers. This CO2/CH4 separation performance is comparable to the previous generation of MMMs based on curable small-molecule IL monomers with the same IL and zeolite. However, this new MMM system also exhibits faster curing gelation times and the ability to be solution-cast onto a porous support for formation of thin-film composite membranes without significant selective layer soak-in.