All-Day Multicyclic Atmospheric Water Harvesting Enabled by Polyelectrolyte Hydrogel with Hybrid Desorption Mode

Sorption-based atmospheric water harvesting (AWH) is a promising approach for mitigating worldwide water scarcity. However, reliable water supply driven by sustainable energy regardless of diurnal variation and weather remains a long-standing challenge. To address this issue, a polyelectrolyte hydrogel sorbent with an optimal hybrid-desorption multicyclic-operation strategy is proposed, achieving all-day AWH and a significant increase in daily water production. The polyelectrolyte hydrogel possesses a large interior osmotic pressure of 659 atm, which refreshes sorption sites by continuously migrating the sorbed water within its interior, and thus enhancing sorption kinetics. The charged polymeric chains coordinate with hygroscopic salt ions, anchoring the salts and preventing agglomeration and leakage, thereby enhancing cyclic stability. The hybrid desorption mode, which couples solar energy and simulated waste heat, introduces a uniform and adjustable sorbent temperature for achieving all-day ultrafast water release. With rapid sorption-desorption kinetics, an optimization model suggests that eight moisture capture-release cycles are capable of achieving high water yield of 2410 mLwater kgsorbent -1 day-1 , up to 3.5 times that of single-cyclic non-hybrid modes. The polyelectrolyte hydrogel sorbent and the coupling with sustainable energy driven desorption mode pave the way for the next-generation AWH systems, significantly bringing freshwater on a multi-kilogram scale closer.

Contiguous High-Mobility Interphase Surrounding Nano-Precipitates in Polymer Matrix Solid Electrolyte

We establish that an interfacial region develops around amorphous Li_1.3Al_0.3Ti_1.7(PO₄)₃ (LATP) nanoparticles in a poly(ethylene oxide) (PEO), which exhibits a 30 times higher Li⁺ mobility than the polymer matrix. To take advantage of this gain throughout the material, nanoparticles must be uniformly dispersed across the matrix, so that the interphase formation is minimally blocked by LATP particle agglomeration. This is achieved using a water-based in situ precipitation method, carefully controlling the temperature schedule during processing. A maximum conductivity of 3.80 × 10^-4 S cm^-1 at 20 °C for an ethylene oxide to Li ratio of 10 is observed at 25 wt % (12.5 vol %) particle loading, as predicted by our tri-phase model. Comparative infrared spectroscopy reveals softening and broadening of the C-O-C stretching modes, reflecting increased disorder in the polymer backbone that is consistent with opening passageways for cation migration. A transition state theory-based approach for analyzing the temperature dependence of the ionic conductivity reveals that thermally activated processes within the interphase benefit more from higher activation entropy than from the decrease in activation enthalpy. The lithium infusion from LATP particles is small, and the charge carriers tend to concentrate in a space-charge configuration near the particle/polymer interface.

High-Entropy Microdomain Interlocking Polymer Electrolytes for Advanced All-Solid-State Battery Chemistries

All-solid-state polymer electrolytes (ASPEs) with excellent processivity are considered one of the most forward-looking materials for large-scale industrialization. However, the contradiction between improving the mechanical strength and accelerating the ionic migration of ASPEs has always been difficult to reconcile. Herein, a rational concept is raised of high-entropy microdomain interlocking ASPEs (HEMI-ASPEs), inspired by entropic elasticity well-known in polymer and biochemical sciences, by introducing newly designed multifunctional ABC miktoarm star terpolymers into polyethylene oxide for the first time. The tailor-made HEMI-ASPEs possess multifunctional polymer chains, which induce themselves to assemble into micro- and nanoscale dynamic interlocking networks with high topological structure entropy. HEMI-ASPEs achieve excellent toughness, considerable ionic conductivity, an appreciable lithium transference number (0.63), and desirable thermal stability (T_d  > 400 °C) for all-solid-state lithium metal batteries. The Li|HEMI-ASPE-Li|Li symmetrical cell shows a stable Li plating/stripping performance over 4000 h, and a LiFePO₄ |HEMI-ASPE-Li|Li full cell exhibits a high capacity retention (≈96%) after 300 cycles. This work contributes an innovative design concept introducing high-entropy supramolecular dynamic networks for ASPEs.

High interfacial-energy heterostructure facilitates large-sized lithium nucleation and rapid Li+ desolvation process

High interfacial energy Li⁰-electrolyte interface contributes to larger Li⁰ nucleation embryos and a more stable interface, so the interfacial energy is essential for highly reversible Li⁰ deposition/stripping. Herein, a high interfacial-energy artificial solid electrolyte interphase (SEI) with rich LiF embedded in lithiated poly-2-acrylamido-2-methylpropane sulfonic acid (PAMPS-Li) network is designed to realize favorable Li⁰ nucleation and rapid desolvation of Li⁺ simultaneously. The Li-F bonds in LiF (001) exhibit stronger ion-dipole interactions with Li atoms, offering higher interfacial energies. When the growth surface energy and total interfacial energy of Li⁰ are balanced, the high interfacial energy SEI with abundant LiF can promote the formation of larger Li⁰ nucleation embryos. In addition, the PAMPS-Li with immobilized anions presents weaker interaction with Li⁰ and possesses higher polymer-Li interfacial energy, and its amide and sulfonic acid groups exhibit higher binding energies with Li⁺. Therefore, PAMPS-Li can easily promote the Li⁺ to escape from the solvent sheath and weaken the desolvation energy barrier. The highly reversible Li⁰ deposition behavior with restricted side reactions is achieved based on the synergistic modification of high interfacial energy SEI with heterostructure. Most importantly, lifespan of multi-layered Li⁰ pouch cell (330 Wh kg^-1) with a low N/P ratio (1.67) is over 100 cycles, verifying its potential practical application.

Macromolecular Design of Lithium Conductive Polymer as Electrolyte for Solid-State Lithium Batteries

In the development of solid-state lithium batteries, solid polymer electrolyte (SPE) has drawn extensive concerns for its thermal and chemical stability, low density, and good processability. Especially SPE efficiently suppresses the formation of lithium dendrite and promotes battery safety. However, most of SPE is derived from the matrix with simple functional group, which suffers from low ionic conductivity, reduced mechanical properties after conductivity modification, bad electrochemical stability, and low lithium-ion transference number. Appling macromolecular design with multiple functional groups to polymer matrix is accepted as a strategy to solve the problems of SPE fundamentally. In this review, macromolecular design based on lithium conducting groups is summarized including copolymerization, network construction, and grafting. Meanwhile, the construction of single-ion conductor polymer is also focused herein. Moreover, synergistic effects between the designed matrix, lithium salt, and fillers are reviewed with the objective to further improve the performance of SPE. At last, future studies on macromolecular design are proposed in the development of SPE for solid-state batteries with high energy density and durability.