Morphological and molecular control of chemical vapor deposition (CVD) polymerized polythiophene thin films.

Oxidative chemical vapor deposition (oCVD) has emerged as one of the most promising techniques for conjugated polymer deposition, especially for unsubstituted polythiophene thin films. oCVD overcomes the insolubility challenge that unsubstituted polythiophene (PT) presents and adds the ability to control morphological and molecular structure. This control is important for enhancing the performance of devices which incorporate organic conductors.

Stable Dendrite-Free Room Temperature Sodium-Sulfur Batteries Enabled by a Novel Sodium Thiotellurate Interface.

The practical application of room-temperature sodium-sulfur (RT Na-S) batteries is severely hindered by inhomogeneous sodium deposition and notorious sodium polysulfides (NaPSs) shuttling. Herein, novel sodium thiotellurate (NaTeS) interfaces are constructed both on the cathode and anode for Na-S batteries to simultaneously address the Na dendritic growth and polysulfides shuttling. On the cathode side, a heterostructural sodium sulfide/sodium telluride embedded in a carbon matrix (NaS/NaTe@C) is rationally designed through a facile carbothermal reaction, where the NaTeS interface will be in situ chemically obtained.

Improved Nitrate-to-Ammonia Electrocatalysis through Hydrogen Poisoning Effects.

Electrochemical conversion from nitrate to ammonia is a key step in sustainable ammonia production. However, it suffers from low productive efficiency or high energy consumption due to a lack of desired electrocatalysts. Here we report nickel cobalt phosphide (NiCoP) catalysts for nitrate-to-ammonia electrocatalysis that display a record-high catalytic current density of -702±7 mA cm, ammonia production rate of 5415±26 mmol g  h and Faraday efficiency of 99.

LaCl-based sodium halide solid electrolytes with high ionic conductivity for all-solid-state batteries.

To enable high performance of all solid-state batteries, a catholyte should demonstrate high ionic conductivity, good compressibility and oxidative stability. Here, a LaCl-based Na superionic conductor (NaZrLaCl) with high ionic conductivity of 2.9 × 10S cm (30 °C), good compressibility and high oxidative potential (3.

Delineating the Impact of Transition-Metal Crossover on Solid-Electrolyte Interphase Formation with Ion Mass Spectrometry.

Lithium-metal batteries (LMB) employing cobalt-free layered-oxide cathodes are a sustainable path forward to achieving high energy densities, but these cathodes exhibit substantial transition-metal dissolution during high-voltage cycling. While transition-metal crossover is recognized to disrupt solid-electrolyte interphase (SEI) formation on graphite anodes, experimental evidence is necessary to demonstrate this for lithium-metal anodes. In this work, advanced high-resolution 3D chemical analysis is conducted with time-of-flight secondary-ion mass spectrometry (TOF-SIMS) to establish spatial correlations between the transition metals and electrolyte decomposition products found on cycled lithium-metal anodes.

Intercalation-type catalyst for non-aqueous room temperature sodium-sulfur batteries.

Ambient-temperature sodium-sulfur (Na-S) batteries are potential attractive alternatives to lithium-ion batteries owing to their high theoretical specific energy of 1,274 Wh kg based on the mass of NaS and abundant sulfur resources. However, their practical viability is impeded by sodium polysulfide shuttling. Here, we report an intercalation-conversion hybrid positive electrode material by coupling the intercalation-type catalyst, MoTe, with the conversion-type active material, sulfur.

Effect of Electrochemical Pre-Lithiation on Layered Oxide Cathodes for Anode-Free Lithium-metal Batteries.

Due to high energy density and lower manufacturing cost, anode-free lithium-metal batteries (AFLMBs) are attracting increasing attention. The challenges for developing them lie in inferior Coulombic efficiency and short cycle life due to the highly reactive lithium metal. Herein, an electrochemical pre-lithiation strategy is applied to layered oxide cathodes, specifically LiNiO and LiCoO , aiming to provide an additional lithium source and understand the effect on the cathode structure for AFLMBs.

Battery Charge Curve Prediction via Feature Extraction and Supervised Machine Learning.

Real-time onboard state monitoring and estimation of a battery over its lifetime is indispensable for the safe and durable operation of battery-powered devices. In this study, a methodology to predict the entire constant-current cycling curve with limited input information that can be collected in a short period of time is developed. A total of 10 066 charge curves of LiNiO -based batteries at a constant C-rate are collected.

Operation of Layered LiCoO to Higher Voltages with a Localized Saturated Electrolyte.

The commercialization of lithium-ion batteries started with a layered LiCoO (LCO) cathode for portable electronics, but only 50% of its theoretical capacity can be used in practical cells due to detrimental surface and bulk degradations when charged to high voltages. We demonstrate here that the stability of the electrolyte plays a critical role in the performance of LCO at high voltages by employing a localized saturated electrolyte (LSE). With a cutoff voltage of 4.

Designing reliable electrochemical cells for operando lithium-ion battery study.

Operando experiments attract increasing attention in lithium-ion batteries (LIBs) studies for their ability to capture non-equilibrium and fast-transient processes during electrochemical reactions. They provide valuable information and mechanisms that cannot be obtained from ex-situ methods. Designing a suitable and reliable electrochemical cell is the first crucial step for most operando studies.

Tailoring Electrode-Electrolyte Interfaces in Lithium-Ion Batteries Using Molecularly Engineered Functional Polymers.

Electrode-electrolyte interfaces (EEIs) affect the rate capability, cycling stability, and thermal safety of lithium-ion batteries (LIBs). Designing stable EEIs with fast Li transport is crucial for developing advanced LIBs. Here, we study Li kinetics at EEIs tailored by three nanoscale polymer thin films via chemical vapor deposition (CVD) polymerization.

Surface Engineering of a LiMnO Electrode Using Nanoscale Polymer Thin Films via Chemical Vapor Deposition Polymerization.

Surface engineering is a critical technique for improving the performance of lithium-ion batteries (LIBs). Here, we introduce a novel vapor-based technique, namely, chemical vapor deposition polymerization, that can engineer nanoscale polymer thin films with controllable thickness and composition on the surface of battery electrodes. This technique enables us to, for the first time, systematically compare the effects of a conducting poly(3,4-ethylenedioxythiophene) (PEDOT) polymer and an insulating poly(divinylbenzene) (PDVB) polymer on the performance of a LiMnO electrode in LIBs.

Thermal conductivity of poly(3,4-ethylenedioxythiophene) films engineered by oxidative chemical vapor deposition (oCVD).

Oxidative chemical vapor deposition (oCVD) is a versatile technique that can simultaneously tailor properties (, electrical, thermal conductivity) and morphology of polymer films at the nanoscale. In this work, we report the thermal conductivity of nanoscale oCVD grown poly(3,4-ethylenedioxythiophene) (PEDOT) films for the first time. Measurements as low as 0.