Byoungwoo Kang

Fast-charging technology for high-energy-density lithium-ion batteries remains constrained by high interfacial impedance and sluggish Li+ transport within electrodes. Herein, hierarchical-sized Li1.5Al0.5Ti1.5(PO4)3 (LATP, particle ranging from 5 to 500 nm) is used to construct a hybrid solid–liquid Li+ transport network in high-mass-loading cathodes (27 mg cm–2). A combination of different characterization techniques is employed to understand the underlying working principle of LATP from the particle to the electrode scale. LATP nanograins (∼10 nm) adsorbed onto cathode particle surfaces reduce Li+ desolvation energy (43.30 vs 52.97 kJ mol–1) and stabilize a thin CEI after cycling. Submicron LATP particles (320–480 nm) infiltrate pores of thick electrodes, forming interconnected networks that increase the Li+ diffusion coefficient. Furthermore, LATP increases the Li+ transference number of the liquid electrolyte within LATP-permeated regions. Consequently, LiNi0.8Co0.1Mn0.1O2||Li cells with LATP-blended cathodes deliver dramatically enhanced rate performance (102 vs 36 mAh g–1 at 0.75C and –10 °C).

Reversible mechanical changes at high voltage enable single-crystal mid-Ni layered oxides to deliver high energy density and stable long-term cycling.

The commercialization of liquid lithium-ion batteries has revolutionized the consumer electronics industry. However, conventional lithium-ion batteries with graphite anodes and organic electrolytes are approaching their intrinsic performance limits and struggle to meet the growing demands for higher energy density, reliability, and safety in electric vehicles and large-scale energy storage. Solid-state batteries utilizing lithium or sodium metal anodes are considered promising next-generation energy storage solutions. Despite this potential, the formation of dendrites during charge–discharge cycling remains a critical challenge. Dendrite growth can initiate a destructive feedback loop of crack propagation and further dendrite intrusion, ultimately leading to battery failure and performance degradation. Previous studies have predominantly focused on single physical domains, such as electrochemical, stress, or thermal fields. However, such single-physics approach limits the understanding of dendrite evolution under realistic, coupled multiphysics conditions. This review first compares the morphological characteristics of dendrites in liquid and solid-state metal batteries. It then critically examines the key factors and predictive models of dendrite formation, initially from single-physics and subsequently from an integrated multiphysics perspective. Finally, strategies for mitigating dendrite growth via multiphysics field regulation are summarized. By establishing a comprehensive framework that integrates morphology evolution, multiphysics modeling, and suppression strategies, this work provides a foundational theoretical understanding for addressing dendrite formation in solid-state lithium and sodium metal batteries.

A high energy density all-solid-state battery via Li percolation network formation.

Lithium-ion batteries, particularly those employing lithium metal-based anodes, have garnered significant attention as energy storage systems due to their high energy density during charge-discharge cycles. However, the fundamental mechanisms underlying the microstructural evolution during cycling remain insufficiently understood. Here, we introduce a rechargeable Li-ion probe specifically designed for real-time transmission electron microscopy (TEM) analysis of electrode materials. The probe withstands electron beam irradiation and preserves its functionality under ambient conditions, enabling repeated in situ TEM measurements. By applying galvanostatic conditions, we employed this Li-ion probe to visualize (de)lithiation processes in both a lithiophilic LiAu₃ electrode and a lithiophobic Ni electrode. Furthermore, this probe is not limited to specific electrode materials but can be adapted for a wide range of battery components, including cathodes, anodes, and current collectors, making it a versatile tool for advanced energy storage research. Our findings demonstrate that the Li-ion probe facilitates critical insights into the interplay between the electrode microstructure and electrochemical behavior, thereby paving the way for advanced battery characterization techniques. This innovation establishes a foundation for future research aimed at unraveling the dynamic behavior of lithium-based electrodes during prolonged cycling.

For highly active electron transfer and ion diffusion, controlling the surface wettability of electrically and thermally conductive 3D graphene foams (3D GFs) is required. Here, we present ultrasimple and rapid superwettability switching of 3D GFs in a reversible and reproducible manner, mediated by solvent-exclusive microwave arcs. As the 3D GFs are prepared with vapors of nonpolar acetone or polar water exclusively, short microwave radiation (≤10 s) leads to plasma hotspot-mediated production of methyl and hydroxyl radicals, respectively. Upon immediate radical chemisorption, the 3D surfaces become either superhydrophobic (water contact angle = ∼170°) or superhydrophilic (∼0°), and interestingly, the wettability transition can be repeated many times due to the facile exchange between previously chemisorbed and newly introduced radicals via the formation of methanol-like intermediates. When 3D GFs of different surficial polarities are incorporated into electric double-layer capacitors with nonpolar ionic liquids or polar aqueous electrolytes, the polarity matching between graphene surfaces and electrolytes results in ≥548.0 times higher capacitance compared to its mismatching at ≥0.5 A g^-1, demonstrating the significance of wettability-controlled 3D GFs.

Out of practicality, ambient air rather than oxygen is preferred as a fuel in electrochemical systems, but CO₂ and H₂O present in air cause severe irreversible reactions, such as the formation of carbonates and hydroxides, which typically degrades performance. Herein, we report on a Na-air battery enabled by a reversible carbonate reaction (Na₂CO₃·xH₂O, x = 0 or 1) in Nasicon solid electrolyte (Na₃Zr₂Si₂PO₁₂) that delivers a much higher discharge potential of 3.4 V than other metal-air batteries resulting in high energy density and achieves > 86 % energy efficiency at 0.1 mA cm⁻² over 100 cycles. This cell design takes advantage of moisture in ambient air to form an in-situ catholyte via the deliquescent property of NaOH. As a result, not only reversible electrochemical reaction of Na₂CO₃·xH₂O is activated but also its kinetics is facilitated. Our results demonstrate the reversible use of free ambient air as a fuel, enabled by the reversible electrochemical reaction of carbonates with a solid electrolyte.

A novel strategy for preventing battery thermal runaway has been proposed. A self-discharge reaction which spontaneously occurs above 100 °C can improve phase stability of the delithiated high Ni cathode via Li _x S-induced lithiation.