Electrochemically Controlled Reversible Formation of Organized Channel Arrays in Nanoscale-Thick RuO₂ Films: Implications for Mechanically Stable Thin Films and Microfluidic Devices

Abstract

Arrays of notched holes were fabricated with shapes that serve to initiate and guide crack formation during electrochemical delithiation of RuO2 films. It is demonstrated that these structures cause the formation of organized microchannel arrays during delithiation and that the channels reversibly close when the films are re-lithiated. Moreover, the maximum width of the channels is a function of the hole spacing, and the widths can be controlled by controlling the state of lithiation. Also, there is a striking improvement in the overall mechanical stability of the films when crack formation is guided in this way. These results are consistent with models for stress accommodation through reversible sliding at the film–substrate interface. The ability to use electrochemical methods to reversibly open and close channels with controlled widths could be of use in microfluidic devices and sensors.

Competitive Redox Chemistries in Vanadium Niobium Oxide for Ultrafast and Durable Lithium Storage

“…3a. Similar with the typical pseudocapacitive RuO 2 anode [30][31][32], T-Nb 2 O 5 demonstrates the typical broad redox peaks in potential range of 1.3-2.1 V, which can be attributed to the stepwise redox process from Nb 5+ to Nb 4+ and then Nb 3+ cause by the Li + insertion [33,34]. However, the most obvious redox peaks for VNbO 4 are located at a low potential range of 1.0-1.5 V, which corresponds to the redox couple of V 3+ /V 2+ , The peak area contributed by Nb redox reaction in potential range of 1.3-2.1 V is significantly reduced, which indicates that the capacity contribution from the redox reaction of Nb is reduced [35].…”

Fluorine-Initiated Carboxyl Group Enhanced Combination Properties of the Polyethylene Separator for Lithium-Ion Batteries

“…Under environmental pressures like global warming and other trends, policies regarding “carbon neutrality” lead us facing a new round of pressure from energy substitution and industrial adjustment. , Among various alternative energy sources, lithium-ion batteries have high energy density, long cycle life, low self-discharge rate, and excellent leading position in environmental protection. − Lithium-ion batteries have been widely used in 3C products, − electric vehicles, energy storage, and other fields in the past 20 years. − Actually, with the continuous improvement in battery capacity and charge–discharge flow of lithium-ion in recent years, higher requirements are put forward for the performance of lithium-ion batteries. − A lithium-ion battery is mainly composed of positive electrode, negative electrode, separator, and electrolyte. Separator is an important part of a lithium-ion battery, and the main role of the separator is to prevent a battery short circuit.…”

Stable Interface between Sulfide Solid Electrolyte and Room-Temperature Liquid Lithium Anode

“…An unstable solid electrolyte interface (SEI) and the exposed surface will consume the lithium source, degrade cycle performance/discharge efficiency, increase internal resistance, generate gas, and reduce safety. Solving the chemical/electrochemical instability issue of the solid–liquid interface is the key to the effective operation of the battery. − Therefore, research on the interfacial problem is at the core of basic Li-ion battery research. In order to stabilize the electrode–electrolyte interface, researchers usually perform modification of the electrode/electrolyte material or electrode/electrolyte surface − or add additives to the electrolyte to form a more stable SEI layer − to obtain good results.…”