Dynamic Electrode-Electrolyte Intermixing in Solid-State Sodium Nano-Batteries.

Nanostructured solid-state batteries (SSBs) are poised to meet the demands of next-generation energy storage technologies by realizing performance competitive to their liquid-based counterparts while simultaneously offering improved safety and expanded form factors. Atomic layer deposition (ALD) is among the tools essential to fabricate nanostructured devices with challenging aspect ratios. Here, we report the fabrication and electrochemical testing of the first nanoscale sodium all-solid-state battery (SSB) using ALD to deposit both the V2O5 cathode and NaPON solid electrolyte followed by evaporation of a thin-film Na metal anode. NaPON exhibits remarkable stability against evaporated Na metal, showing no electrolyte breakdown or significant interphase formation in the voltage range of 0.05-6.0 V vs Na/Na+. Electrochemical analysis of the SSB suggests intermixing of the NaPON/V2O5 layers during fabrication, which we investigate in three ways: in situ spectroscopic ellipsometry, time-resolved X-ray photoelectron spectroscopy (XPS) depth profiling, and cross-sectional cryo-scanning transmission electron microscopy (cryo-STEM) coupled with electron energy loss spectroscopy (EELS). We characterize the interfacial reaction during the ALD NaPON deposition on V2O5 to be twofold: (1) reduction of V2O5 to VO2 and (2) Na+ insertion into VO2 to form NaxVO2. Despite the intermixing of NaPON-V2O5, we demonstrate that NaPON-coated V2O5 electrodes display enhanced electrochemical cycling stability in liquid-electrolyte coin cells through the formation of a stable electrolyte interphase. In all-SSBs, the Na metal evaporation process is found to intensify the intermixing reaction, resulting in the irreversible formation of mixed interphases between discrete battery layers. Despite this graded composition, the SSB can operate for over 100 charge-discharge cycles at room temperature and represents the first demonstration of a functional thin-film solid-state sodium-ion battery.

Nanoscale Li, Na, and K ion-conducting polyphosphazenes by atomic layer deposition.

A key trailblazer in the development of thin-film solid-state electrolytes has been lithium phosphorous oxynitride (LiPON), the success of which has led to recent progress in thin-film ion conductors. Here we compare the structural, electrochemical, and processing parameters between previously published LiPON and NaPON ALD processes with a novel ALD process for the K analogue potassium phosphorous oxynitride (KPON). In each ALD process, alkali tert-butoxides and diethylphosphoramidate are used as precursors. To understand the ALD surface reactions, this work proposes a reaction mechanism determined by in-operando mass spectrometry for the LiPON process as key to understanding the characteristics of the APON (A = Li, Na, K) family. As expected, NaPON and LiPON share similar reaction mechanisms as their structures are strikingly similar. KPON, however, exhibits similar ALD process parameters but the resulting film composition is quite different, showing little nitrogen incorporation and more closely resembling a phosphate glass. Due to the profound difference in structure, KPON likely undergoes an entirely different reaction mechanism. This paper presents a comprehensive summary of ALD ion conducting APON films as well as a perspective that highlights the versatility of ALD chemistries as a tool for the development of novel thin film ion-conductors.

Atomic Layer Deposition of Sodium Phosphorus Oxynitride: A Conformal Solid-State Sodium-Ion Conductor.

The development of novel materials that are compatible with nanostructured architectures is required to meet the demands of next-generation energy-storage technologies. Atomic layer deposition (ALD) allows for the precise synthesis of new materials that can conformally coat complex 3D structures. In this work, we demonstrate a thermal ALD process for sodium phosphorus oxynitride (NaPON), a thin-film solid-state electrolyte (SSE), for sodium-ion batteries (SIBs). NaPON is analogous to the commonly used lithium phosphorus oxynitride SSE in lithium-ion batteries. The ALD process produces a conformal film with a stoichiometry of Na4PO3N, corresponding to a sodium polyphosphazene structure. The electrochemical properties of NaPON are characterized to evaluate its potential in SIBs. The NaPON film exhibited a high ionic conductivity of 1.0 × 10-7 S/cm at 25 °C and up to 2.5 × 10-6 S/cm at 80 °C, with an activation energy of 0.53 eV. In addition, the ionic conductivity is comparable and even higher than the ionic conductivities of ALD-fabricated Li+ conductors. This promising result makes NaPON a viable SSE or passivation layer in solid-state SIBs.

Evaluation of trichodynia (hair pain) during chemotherapy or tamoxifen treatment in breast cancer patients.

INTRODUCTION: In women receiving antineoplastic therapy, hair loss is often accompanied by distressing hair or scalp sensations, such as hair pain (trichodynia) and pruritus. A scientific approach to objectively evaluate the course and characteristics of these unpleasant sensations is of great importance for the establishment of treatment strategies. METHODS: An observational cohort study was conducted in 34 female breast cancer patients, postoperatively undergoing chemotherapy (group C, n = 17) or endocrine therapy with tamoxifen (group T, n = 17). For 28 weeks after therapy initiation, patients experiencing hair pain and/or scalp pruritus were required to complete a specially developed diary, based on a modification of pain questionnaires. Sensations were journalized in terms of time of onset, duration, intensity on a numeric rating scale, dependence on touching the scalp or hair and character of the sensation, chosen from given descriptors or using own words. RESULTS: In group C, all patients who completed the questionnaire experienced hair and scalp sensations: 87% both trichodynia and pruritus, 13% trichodynia only. Reported intensities ranged between 1 and 10. In group T, 31% of participants reported hair and scalp sensations: 12% both trichodynia and pruritus, 12% pruritus only, 7% trichodynia only. Intensities were rated between 1 and 5. No sensations were reported after week 11 in either group. CONCLUSIONS: Hair and scalp sensations in group C were significantly more common, lasted longer, and were of greater intensity and more differentiated qualities than in group T. The occurrence of trichodynia in chemotherapy patients corresponded with the onset and duration of hair loss, thus suggesting a possible correlation.

Analysis of quantitative changes in hair growth during treatment with chemotherapy or tamoxifen in patients with breast cancer: a cohort study.

BACKGROUND: In women with breast cancer, chemotherapy-induced alopecia is a highly feared but common side-effect of antineoplastic treatment. The onset, pattern and amount of hair loss differ depending on the therapy regimen and have not yet been quantified using standardized techniques. OBJECTIVES: To evaluate objectively and compare the effect of antineoplastic therapy with chemotherapy or tamoxifen on hair loss, quantifying trichological parameters. METHODS: Female patients with breast cancer were included (n = 34), who were receiving chemotherapy (group C, n = 17) or tamoxifen (group T, n = 17) after surgery. Trichological parameters were evaluated once before [week 0 (w0)], twice during (w3, w6) and twice after (w18, w28) the normal 16-week course of chemotherapy, or at corresponding time points during continuous tamoxifen intake. At each visit, anagen and telogen hairs and hair density were quantified by automated phototrichogram in two defined areas: frontal and occipital. RESULTS: Group T generally showed no changes in anagen and telogen hairs or hair density. In group C, anagen hairs and hair density generally followed the same course, decreasing until w6, remaining at a low level during w6-18 and increasing after cessation of chemotherapy, reaching values comparable with or higher than baseline at w28. Telogen hairs increased until w3 then decreased until w6, remaining stable afterwards. CONCLUSIONS: Diffuse hair loss begins shortly after initiation of chemotherapy, mainly as anagen effluvium, with a proportion of anagen to telogen conversion. Hair loss is most prominent after 6 weeks of chemotherapy. Within 3 months after cessation of chemotherapy, hair growth rate returns to baseline values. Tamoxifen did not affect hair growth parameters.