Research Digest — 2026-05-07¶
Halide Solid Electrolytes¶
1. Grain Boundary Space Charge Engineering of Solid Oxide Electrolytes: Model Thin Film Study¶
Source: Advanced Functional Materials (10.1002/adfm.202517177) · 📅 2026-05 · ↗ Open paper
Demonstrates systematic control of grain boundary (GB) resistance in Gd-doped CeO₂ solid electrolytes by up to 12 orders of magnitude through selective GB chemistry modification. By growing thin films on MgO vs Al₂O₃ substrates and inducing selective cation in-diffusion into GBs, the authors tune the GB core charge density, directly linking it to space charge potential barriers. Mg²⁺ in-diffusion reduces positive core charge and nearly eliminates the GB barrier, while Al³⁺ increases it.
Relevance to DENG.Group
Directly relevant to Cheng Peng's grain boundary research. The methodology of selectively engineering GB chemistry without altering bulk properties provides a clean experimental model for validating computational predictions of space charge effects. The quantitative link between GB core charge and barrier height could inform the group's modeling of GB transport in Li-ion solid electrolytes. The approach of controlling GB properties via substrate-mediated diffusion is transferable to other electrolyte systems.
2. Synergistic activation of grain boundaries with dual salts enables fast lithium percolation in LATP-based solid state electrolytes¶
Source: Journal of Materials Chemistry A (10.1039/D5TA09848C) · 📅 2026-05 · ↗ Open paper
Uses a dual-salt strategy during cold sintering of LATP (Li₁₊ₓAlₓTi₂₋ₓ(PO₄)₃) to activate grain boundaries for fast Li⁺ percolation, achieving a record room-temperature ionic conductivity of 2.02 × 10⁻³ S cm⁻¹. Through combined ssNMR, TEM, XPS, and KPFM characterization, the authors show that dual salts increase Li₃-site occupancy within grains, competitively substitute anions on oxygen vacancies to widen conduction channels, and induce Li⁺ enrichment and short-range ordering at GBs.
Relevance to DENG.Group
Highly relevant to Cheng Peng's GB work and the broader group's interest in interface transport. The dual-salt cold sintering approach — which modifies both grain interiors and boundaries simultaneously — is a practical processing strategy that could be adopted for other solid electrolyte systems. The finding that GB Li⁺ enrichment and ordering enhances transport is a useful benchmark for computational models of GB conduction.
Polymer Electrolytes¶
3. Suppressing concentration polarization in lithium battery composite polymer electrolytes via piezo-assisted electromechanical coupling effect¶
Source: Nature Communications (s41467-026-72527-0) · 📅 2026-04-30 · ↗ Open paper
Creates a piezoelectric composite polymer electrolyte (PVDF blended with BZT-BCT piezoelectric particles) that exploits volume fluctuations of lithium metal anodes during cycling to generate a gradient piezo-field. This field selectively accelerates Li⁺ while impeding anion movement, fundamentally suppressing concentration polarization. The electrolyte achieves a high critical current density of 3.7 mA cm⁻² and enables stable Li||NCM811 cycling for over 2600 cycles at 900 mA g⁻¹ (2.8–4.5 V).
Relevance to DENG.Group
Relevant to the group's solid polymer electrolyte research interest. The piezo-assisted coupling concept — converting unavoidable anode volume changes into a beneficial internal field — is an innovative approach to the concentration polarization problem in SPEs. The mechanoelectrochemical coupling could inspire new multiphysics modeling directions for the group.