Spent graphite from end-of-life Li-ion batteries as a potential electrode for aluminium ion battery

Graphite is central in almost all commercial Li-ion batteries (LIBs) and possesses attractive physical and chemical properties such as good ionic conductivity and layered graphitic structure. In this communication, we have demonstrated the recycling of graphite from end-of-life LIBs and the re-purposing of the recovered material for positive electrodes in next-generation aluminium-ion-batteries (AIBs). The recovered graphite possesses enlarged interlayer spacing which is shown to effectively boost Al-ion insertion/de-insertion during the charge/discharge processes. Excellent Al-ion storage performance is achieved with the capacity reaching 124 mAh g⁻¹ at 50 mA g⁻¹. The material retained a capacity of 55 mAh g⁻¹ even after the applied current was increased to 500 mA g⁻¹, showing its capability to deliver high rate performance. The charge/discharge cycling further revealed that the graphite retains 81% of its initial capacity even after 6700 cycles at a high rate of 300 mA g⁻¹. This excellent aluminium ion storage performance makes the recovered graphite a promising positive electrode material, providing a possible solution for the recycling of huge amounts of LIB scrap. At the same time, this material aids the development of alternative sustainable battery technology, as an alternative to LIBs.Hong Duc Pham, Michael Horn, Joseph F.S. Fernando, Rohan Patil, Manisha Phadatare, Dmitri Golberg, Håkan Olin, Deepak P. Duba

True meaning of pseudocapacitors and their performance metrics: asymmetric versus hybrid supercapacitors

First published: 06 August 2020The development of pseudocapacitive materials for energy-oriented applications has stimulated considerable interest in recent years due to their high energy-storing capacity with high power outputs. Nevertheless, the utilization of nanosized active materials in batteries leads to fast redox kinetics due to the improved surface area and short diffusion pathways, which shifts their electrochemical signatures from battery-like to the pseudocapacitive-like behavior. As a result, it becomes challenging to distinguish "pseudocapacitive" and "battery" materials. Such misconceptions have further impacted on the final device configurations. This Review is an earnest effort to clarify the confusion between the battery and pseudocapacitive materials by providing their true meanings and correct performance metrics. A method to distinguish battery-type and pseudocapacitive materials using the electrochemical signatures and quantitative kinetics analysis is outlined. Taking solid-state supercapacitors (SSCs, only polymer gel electrolytes) as an example, the distinction between asymmetric and hybrid supercapacitors is discussed. The state-of-the-art progress in the engineering of active materials is summarized, which will guide for the development of real-pseudocapacitive energy storage systems.Nilesh R. Chodankar, Hong Duc Pham, Ashok Kumar Nanjundan, Joseph F. S. Fernando, Kolleboyina Jayaramulu ... Deepak P. Dubal ... et al

Enriched pseudocapacitive lithium storage in electrochemically activated carbonaceous vanadium(iv,v) oxide hydrate

Hydrated vanadium oxides (HVOs) are promising (extrinsic) pseudocapacitive materials that extend the possibility to optimize electrochemical performance through fine-tuning their nanoscale porosity, structural disorder and conventional composition. These materials demonstrate the features of batteries (i.e. high energy density) and supercapacitors (fast power output). However, most pseudocapacitive oxides are characterized by poor conductivity, which leads to high electrode resistance. Herein, an amorphous-like carbon-integrated vanadium oxide hydrate (V5O12·0.4H2O, CHVO) is engineered using a straightforward solvothermal approach, with improved conductivity, rich pore architecture and readily available nanoscale redox-active sites. The CHVO material shows superior performance as an anode in Li-ion batteries with a specific capacity of 1175 mA h g−1 at 50 mA g−1 in the 150th cycle, which was maintained to 525 mA h g−1 over 600 cycles at 1000 mA g−1. The half-cell can be charged to 403 mA h g−1 (1451 C g−1) at 4000 mA g−1 in ∼6 min. The cyclic voltammetry analysis shows that CHVO undergoes an electrochemical activation by forming a stable lithium vanadium oxide in the initial cycles. The research on electrochemical de(lithiation) mechanism of HVOs at low potentials (<1 V) is largely unexplored. In this context, real time measurements using in situ Transmission Electron Microscopy are provided to underpin the Li-ion transport process in CHVO electrodes. It is revealed that the carbon framework and peculiar structure of CHVO effectively buffer large volume expansions upon (de)lithiation. In addition, ex situ X-ray photoelectron spectroscopy and X-ray Diffraction measurements were collectively utilized to uncover a conversion-type reaction mechanism.Joseph F. S. Fernando, Dumindu P. Siriwardena, Konstantin L. Firestein, Chao Zhang, Joel E. von Treifeldt, Deepak P. Dubal ... et al

Análise de coeficiente de trilha para os componentes de produção em arroz Path coefficient analysis of rice yield components

Com o objetivo de avaliar a influência dos componentes de produção de arroz no rendimento de grãos através da análise de trilha, avaliaram-se 88 genótipos de arroz em quatro anos agrícolas. Em cada ano, os experimentos foram conduzidos no delineamento em blocos completos casualizados, com quatro repetições. As variáveis analisadas foram: estatura de plantas, rendimento de grãos, esterilidade de espiguetas, número de grãos por panícula, massa de mil grãos e rendimento de engenho. As análises de variância, correlação e de trilha (Path Analysis) foram realizadas para cada variável, utilizando-se o programa computacional GENES. Os genótipos avaliados apresentaram diferenças significativas para todas as variáveis analisadas, nos quatro anos de experimento. A seleção de variáveis deve ser realizada em grupos de cultivares semelhantes entre si e a utilização de um maior número de variáveis possibilita melhores inferências sobre os componentes da produção do arroz. A massa de grãos é o componente de produção que mais afeta o rendimento da cultura do arroz.<br>Eighty eight rice genotypes were evaluated during four years aiming to study the relationship among yield components. In each year, the experimental design was a completely randomized block design with four replications and the variables studied were: plant height, seed yield, spikelet sterility, number of seeds per panicle, 1000 seeds weight and head grains. The estimation of correlations and the path coefficient analysis were conducted with the GENES software. The genotypes showed significant variability for all the variables analyzed within each one of years. It was concluded that variable selection must be carried out among the cultivars that are more similar and using a greater number of variables allows better inferences about rice yield components. Grain weight was the yield of component that most affected seed yield rice plants

Uso prático de marcadores moleculares para seleção assistida no melhoramento de uvas de mesa apirênicas

A hipótese mais bem aceita atualmente para explicar a genética complexa da estenoespermocarpia, observada na videira, indica que a expressão deste fenótipo é controlada por três genes recessivos, independentemente herdados e controlados por um gene regulador dominante (sdI). Em estudo anterior, Lahogue et al. (1998) identificaram um marcador RAPD (Random Amplified Polymorphic DNA) ligado ao gene sdI e utilizaram-no para desenvolver um SCAR (Sequence Characterized Amplified Region) co-dominante denominado SCC8, que pode distinguir, em uma progênie, indivíduos com semente como também selecionar indivíduos apirênicos. Neste trabalho, são apresentados resultados da avaliação do potencial de aplicação do marcador molecular SCAR SCC8 para seleção assistida do caráter da apirenia no melhoramento de uvas de mesa sem sementes. A utilização deste marcador na seleção assistida para apirenia em uvas de mesa mostrou-se viável, e as conseqüências da sua utilização no programa de melhoramento da Embrapa Uva e Vinho são discutidas

Effect of fertilization with fluid swine slurry on production and nutritive value of Tifton 85 Efeito da fertilização com esterco líquido de suínos sobre a produção e o valor nutritivo do capim-tifton 85

The objective of this study was to evaluate the effect of different doses of liquid swine slurry on dry matter accumulation rate and nutritive values (crude proten and neutral detergent fiber) of Tifton 85 grass pasture cultivated in southwestern Paraná from October 2005 to March 2006. It was used a complete random experimental design in a 4 x 4 factorial scheme composed of four doses of swine slurry in the plots (0, 80, 160 and 320 m³/ha) and four consecutive cuts in the subplots of the pasture. It was carried out two applications, one in the beginning of the experiment and other after 80 days. Cuts were performed every time pasture height was 40 cm. There was a dose versus cut interaction for all variables. Swine slurry promoted increase on dry matter accumulation rate only on the first cut after its application (cuts 1 and 3). Dry matter maximal yield (24.2 t/ha) was obtained at 249 m³/ha of swine slurry manure (143 and 106 m³/ha, respectively for applications 1 and 2), corresponding to 450 kg of N/ha. Percentage of crude protein increases and neutral detergent fiber of Tifton 85 grass decreases as dose of swine slurry increases, improving forage nutritive value. Use efficiency and nitrogen recovery rate decrease with addition of swine slurry doses.<br>Objetivou-se avaliar o efeito de diferentes doses de dejeto líquido de suínos sobre a taxa de acúmulo de matéria seca e o valor nutritivo (proteína bruta e fibra em detergente neutro) de uma pastagem de capim-tifton 85 cultivada na região sudoeste do Paraná no período de outubro de 2005 a março de 2006. Utilizou-se delineamento experimental de blocos ao acaso em esquema fatorial de 4 x 4, composto por quatro doses de dejetos líquidos de suínos nas parcelas (0, 80, 160 e 320 m³/ha) e quatro cortes consecutivos nas subparcelas da pastagem. Foram realizadas duas aplicações, uma no início do experimento e outra 80 dias após. Os cortes foram realizados sempre que a altura da pastagem atingisse 40 cm. Houve interação dose versus corte para todas as variáveis. Os dejetos promoveram aumento na taxa de acúmulo de matéria seca somente no primeiro corte após sua aplicação (cortes 1 e 3). O rendimento máximo de matéria seca (24,2 t/ha) foi obtido na dose de 249 m³/ha de dejetos (143 e 106 m³/ha, respectivamente, para as aplicações 1 e 2), correspondentes a 450 kg/ha de nitrogênio. O percentual de proteína bruta aumenta e o de fibra em detergente neutro do capim-tifton 85 diminui com o aumento da dose de dejetos, melhorando o valor nutritivo da forragem. A eficiência de utilização e a taxa de recuperação do nitrogênio diminuem com o incremento da dose de dejetos líquido de suínos

Epidemiologia das encefalites por arbovírus na amazônia brasileira Epidemiology of encephalitis by arboviruses in the Amazon region of Brazil

Os autores revêem os aspectos ecoepidemiológicos apresentados pelos virus da encefalite de St. Louis (SLE), encefalites equinas Leste (EEE), Oeste (WEE) e Venezuelana [subtipos III, Mucambo (MUC) e IV, Pixuna (PIX)], decorrentes dos estudos realizados em diversas áreas da Região Amazônica brasileira, especialmente ao longo das rodovias e projetos de desenvolvimento. Esses vírus são amplamente distribuídos na Amazônia e pelo menos quatro deles, EEE, WEE, MUC e SLE já demonstraram ser patógenos do homem. O diagnóstico da doença humana foi feito por sorologia, sendo que de MUC e SLE obteve-se também isolamento viral. O vírus PIX, parece ser o menos prevalente e foi isolado em poucas oportunidades. Virtualmente se desconhecem os vetores do PIX e WEE. As aves silvestres constituem os hospedeiros principais de todos esses vírus, exceto do MUC, para o qual constituem os roedores. O quadro clínico apresentado pelos pacientes infectados na Amazônia é discutido, comparando-o ao apresentado em outras áreas, especialmente nos EUA, onde periodicamente SLE, EEE e WEE causam surtos de doença humana. Nenhuma epidemia foi até o presente detectada, embora em 1960 uma epizootia em eqüinos causada pelo EEE tenha sido registrada em Bragança, Pará, onde em um rebanho de 500 animais ocorreu uma letalidade de 5%. Quatro outras pequenas epizootias determinadas pelo SLE ocorreram nas florestas adjacentes a Belém, envolvendo aves silvestres e animais sentinelas.<br>An overview of ecological, epidemiological and clinical findings of potential arthropod-borne encephalitis viruses circulating in the Amazon Region of Brazil are discussed. These viruses are the Eastern Equine Encephalitis (EEE), Western Equine Encephalitis (WEE), St. Louis Encephalitis (SLE), Mucambo (MUC) and Pixuna (PIX). These last two are subtypes (HI and IV) of Venezuelan Equine Encephalitis virus. The areas of study were the highways and projects of development, as well as places where outbreaks of human diseases caused by arboviruses had been detected. These viruses are widespread in all Amazonia, and at least four of them, EEE, WEE, SLE and MUC are pathogenic to man. EEE and WEE infections were detected by serology, while SLE and MUC by either serology and virus isolation. The PIX virus has the lowest prevalence and, it was isolated in only a few cases, one being from a laboratory infection. Wild birds are the main hosts for all these viruses, except MUC, whose major hosts are rodents. The symptoms presented by infected people were generally a mild febrile illness. Although, jaundice was observed in two individuals from whom SLE was isolated. A comparison of the clinical symptoms presented by the patients in the Amazon Region and other areas of America, especially in the USA is made. In Brazilian Amazon region epidemics have not been detected although, at least, one EEE epizootic was recorded in Bragança, Para State, in 1960. At that time, of 500 horses that were examined 61% were positive to EEE by HI and of mem 8.2% died On the other hand. SLE has caused four epizootics in a forest near Belem. Wild birds and sentinel monkeys were infected, but no human cases were reported