What particle verbs have to do with grammatical aspect in early child english

The current study investigates the relation between aspect and particle verbs in the acquisition of English. Its purpose is to determine whether children associate telicity, as argued in previous studies, or rather perfectivity, which entails completion of a telic situation, with their early particle verb use. The study analyzes naturalistic data of four monolingual children between 1;6 and 3;8 from CHILDES acquiring English as their first language. On the one hand, it finds that children use both –ed and irregular perfective morphology with simplex verbs before particle verbs. They further use imperfective before perfective morphology with particle verbs. These findings suggest that there is no correlation between telic particle verbs and perfective morphology, as would have been predicted on an account which claims that lexical aspect of predicates guides the acquisition of grammatical aspect (Olsen & Weinberg 1999). On the other hand, the study finds that the children’s particle verbs denote telic situations from early on, but not half of them were used to refer to situations that are also completed. This finding questions analyses which claim that, at an initial stage, children will only interpret predicates as telic if they refer to situations that are at the same time completed. Completion information is not necessary for children in order to use particle verbs correctly for telic situations, as would have been predicted on an extended account along the lines of Wagner (2001). As a conclusion, it is suggested that the divergent findings result from a difference in methodology. While restrictions of perfective and imperfective morphology to particular classes of lexical aspect pertain to the production of grammatical aspect morphology, perfective and imperfective viewpoints on situations pertain to the level of interpretation of telic and atelic situations

Comparing the Solid Electrolyte Interphases on Graphite Electrodes in K and Li Half Cells

In both Li-ion and K-ion batteries, graphite can be used as the negative electrode material. When potassium ions are stored electrochemically in the graphite host, the electrode capacities fade faster than in the lithium ion counterpart. This could be due to the high reactivity of the potassium metal counter electrode (CE) in half cells or a less stable solid electrolyte interphase (SEI) in the potassium case. Previous surface studies on graphite electrodes cycled in K half cells have focused on the SEI characteristics of different electrolyte formulations or different states of charge. In this study, we exploit the fact that graphite can store both lithium and potassium ions. Cell and component parameters have been largely maintained the same, with the only differences between Li and K half cells being the cation of the electrolyte salt and the alkali metal at the CE. The SEI layers formed under these conditions in either setup are studied using X-ray photoelectron spectroscopy with the aim to draw a direct comparison between the surface layers in both charged and discharged states. The results show a considerable crosstalk under OCV conditions between K-metal and the working electrode. Furthermore, the relative SEI layer composition after cycling varies considerably between Li and K half cells. Different dominant SEI species are present depending on the alkali metal used. The strong capacity fade observed in graphite–K half cells is likely linked to much smaller concentrations of inorganic compounds, such as KF, and increased amounts of organic compounds in the SEI

Performance-Determining Factors for Si–Graphite Electrode Evaluation: The Role of Mass Loading and Amount of Electrolyte Additive

The mass loading of Si–graphite electrodes is often considered as a parameter of secondary importance when testing their electrochemical performance. However, if a sacrificial additive is present in the electrolyte to improve the electrochemical performance, the electrode loading becomes the battery cycle-life-determining factor. The correlation between mass-loading, electrolyte additive, and binder type was investigated by analyzing the cycling behavior of Si–graphite electrodes, prepared with water-based binders, with mass loading ranging from 3 to 9.5 mg cm$^{−2}$ and cycled with FEC electrolyte additive, while keeping electrolyte amount constant. A lower loading was obtained by keeping slurry preparation steps unchanged from binder to binder and resulted in a longer lifetime for some of the binders. When the final loading was kept constant instead, the performance became independent of the binder used. Since such results can lead to the misinterpretation of the influence of electrode components on the cycling stability (and to a preference of one binder over another in our case), we propose that a comparison of long-term electrochemical performance data of Si–graphite electrodes needs to be always collected by using the same mass-loading with the constant electrolyte and additive

Degradation Phenomena in Silicon/Graphite Electrodes with Varying Silicon Content

The degradation phenomena of Silicon/Graphite electrodes and the effect of FEC as electrolyte additive was investigated through galvanostatic cycling, XPS analyses and SEM cross section analyses. To understand the direct influence of silicon on the electrode degradation, the silicon amount was varied between 0%–30%. By evaluating the cycling performance and the accumulated capacity loss of the different Si/Gr electrodes (cycled with and without 10 vol-% of FEC), we see that the capacity decay can be distinguished into two phenomena, where one is independent of the Si/Gr ratio while the other one depends on the Si content. As expected, adding FEC improves the cell performance and minimizes the capacity decay. Combing our XPS data and SEM cross section analyses on cycled electrodes, this improvement stems from a thin and flexible SEI including poly(vinyl carbonate) that helps maintaining the overall electrode integrity as we observe less electrode fractures and less pronounced thickness increase. Si/Gr electrodes with 10 and 20% Si content showed very similar accumulated irreversible capacity losses over 100 cycles indicating that with 10 % FEC as electrolyte additive, also higher Si contents could be feasible for future high energy density anodes

Revealing the Formation of Dialkyl Dioxahexane Dioate Products from Ethylene Carbonate Based Electrolytes on Lithium and Potassium Surfaces

In this study, the formation of dicarbonate degradation products of ethylene carbonate-based carbonate mixtures containing dimethyl carbonate, ethyl methyl carbonate or diethyl carbonate that were combined with lithium or potassium metal, is investigated. It is shown by NMR and GCMS that the dicarbonate products dimethyl dioxahexane dioate, ethyl methyl dioxahexane dioate and diethyl dioxahexane dioate are formed from the reactants to different extents and, in particular, the potassium surface initiates the fast formation of the corresponding dicarbonate products. Experiments with deuterated DMC suggest an intermolecular mechanism of the dicarbonate formation. In cell tests, namely potassium vs. graphite, it is shown that the electrolyte formulation with the lowest tendency to dicarbonate formation (EC/DEC) exhibited the best cell stability respectively lowest cell aging

Interphase formation with carboxylic acids as slurry additives for Si electrodes in Li-ion batteries. Part 1: performance and gas evolution

Rendering the solid electrolyte interphase and the inter-particle connections more resilient to volume changes of the active material is a key challenge for silicon electrodes. The slurry preparation in a buffered aqueous solution offers a strategy to increase the cycle life and capacity retention of silicon electrodes considerably. So far, studies have mostly been focused on a citrate buffer at pH = 3, and therefore, in this study a series of carboxylic acids is examined as potential buffers for slurry preparation in order to assess which chemical and physical properties of carboxylic acids are decisive for maximizing the capacity retention for Si as active material. In addition, the cycling stability of buffer-containing electrodes was tested in dependence of the buffer content. The results were complemented by analysis of the gas evolution using online electrochemical mass spectrometry in order to understand the SEI layer formation in presence of carboxylic acids and effect of high proton concentration

Potential and Limitations of Research Battery Cell Types for Electrochemical Data Acquisition

Developing new electrode materials and/or electrolytes for lithium-ion batteries requires reliable electrochemical testing thereof. For this purpose, in academic research typically hand-made coin-type cells are assembled. Their advantage is a rather cheap and facile assembly, and possibility to prepare full-cells as well as half-cells, meaning cathode-anode or electrode-elemental lithium configurations. Critical parameters for testing data quality and the potential and limitations of cell tests in half-cell configuration are discussed. Further, on the basis of a round robin test, using highly homogenous commercial electrodes, where graphite is used as anode and LiNi0.33Mn0.33Co0.33O2 (NMC111) as the cathode material, it is shown that data acquired is highly influenced by assembling parameters. Besides known variables such as the amount of electrolyte or electrode positioning, the proper height of the cell stack and the steel grade of the housing material are identified as decisive variables. Finally, it is demonstrated that under proper conditions coin cells can show a great cycle stability of >2200 cycles using 1C as dis-/charge rate while retaining a capacity of 80%. This performance is close to pouch-type cells containing the same electrodes and electrolyte, which were used as a benchmark system and showed >3500 cycles of lifetime