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The search for advanced electrode materials in K-ion batteries (KIBs) is a significant challenge due to the lack of an efficient throughput screening method in modern battery technology. Layered oxide cathode materials, KxMnO2, have been widely investigated for KIB application due to their high energy and power density. However, KxMnO2 suffers from structural instability and highly hygroscopic nature. To address these issues, here, a combined machine learning (ML) and first-principles method based on density functional theory (DFT) for screening and experimental validation is developed for the first time. This method is used for designing stable KxMnO2 that can reinforce the structural and environmental stabilities as well as high electrochemical performances. Among the large number of candidates, notably, the ML and DFT-assisted strategies identify P′3-type K0.3Mn0.9Cu0.1O2 (KMCO) as a promising candidate for a high performance KIB cathode. Finally, the experimental protocol proves that the KMCO cathode has substantially improved K-storage properties with high-power density and cycling stability even after four weeks air-exposure period. We believe that this study opens a new avenue for identifying and developing suitable electrode materials for future battery applications.

A facile method with one-pot polyol-assisted pyro-technique has been adopted to synthesize highly crystalline, carbon-coated LiMn2O4 (LMO/C) nanoparticles for using as a cathode material in rechargeable Li-ion battery (LIB) applications. this study shows the efficacy of a simple and low-cost pyro-synthesis to realize high performance nano-sized particle electrodes with uniform carbon coating for useful energy storage applications. As using X-ray techniques, we confirmed The phase purity, structure and stoichiometry of the prepared cathode. Electron microscopy studies established that the synthetic technique facilitated the production of nano-sized LMO particles with uniform carbon coating. LMO/C cathode demonstrates excellent electrochemical properties (cycling stabilities of 86% and 77.5% and high rate capabilities of 79% and 36% within the potential windows of 3.3–4.3V and 2.5–4.3V, respectively). The high electrochemical performance of the LMO/C cathode is attributed to the nano-size of the LiMn2O4 particles enabling high surface area and hence greater lithium insertion and also the uniform amorphous carbon coating facilitating effective reduction in manganese dissolution and volume expansion during the lithium de-intercalation/intercalation reactions

Research attention in aqueous rechargeable zinc-ion batteries (ARZIBs) is growing immensely because of their low-cost and eco-friendly cell components. However, its challenging to find new cathode materials towards practical application of ARZIBs. In this contribution, ground-breaking work on the potassium-pillared V2O5.nH2O (K0.5V2O5.nH2O) nanorod with exposed layer structure as high-performance cathode for ARZIB is presented. The storage mechanism of the K0.5V2O5.nH2O cathode in ARZIB is systematically elucidated using a combined of in situ synchrotron X-ray diffraction, ex situ synchrotron X-ray absorption spectroscopy, ex situ TEM analyses, and first-principle calculations. The K0.5V2O5. nH2O cathode displays a notable discharge capacity of 439 mAh g−1 at a current density of 50 mA g−1. Furthermore, it recovers 96% of the capacity after 1500 cycles at 8000 mA g−1. Impressively, the Zn/K0.5V2O5.nH2O battery offers a specific energy of 121 Wh kg−1 at a high specific power of 6480 W kg−1. The superior performance of the cathode is attributed to its unique exposed layer structure with high surface energy, high conductivity, and low migration barrier. The zinc (Zn) insertion pathway into K0.5V2O5.nH2O was studied using density function theory (DFT). This study provides an insight for designing high-performance cathode materials for ARZIBs and other electrochemical systems.

A uniform carbon-coated Na3V2(PO4)2O2xF3 − 2x (NVPOF/C) nanoparticle synthesized by a novel pyro synthesis method is utilized for sodium-ion batteries (SIBs) as a cathode. Remarkably, the electrochemical properties are performed at high rates show significantly improved discharge capacity (Fig. 1). At 0.1 C, the NVPOF/C cathode shows a discharge capacity of 130 mAh g− 1, corresponding to 100% of the theoretical capacity. Even at 50 C, a discharge capacity of ~85 mAh g− 1 could be attained. The in situ X-ray diffraction and ex-situ synchrotron X-ray absorption near edge structure spectroscopy results exposed that the reversible sodium ion insertion/ extraction into/from NVPOF/C host structure occurs with a small volume change (3.4%), indicating the structural stability of the cathode. Our study validates that the Na3V2(PO4)2O2xF3 − 2x/C electrode is a promising candidate for developing high power/ energy density cathodes for SIBs. Figure 1. (a) Galvanostatic charge/discharge potential profiles of Na3V2(PO4)2O2xF3-2x in the potential range of 2.0 ~ 4.3V at 0.1C. (b) Cycle performance at 1C. (c) The discharge profiles of different C. (d) Comparison of the rate capabilities at various curve Figure 1

Energy storage devices remain critical to meet the increasing demands of the modern society. Rechargeable lithium ion batteries (LIBs) are a crucial finding in this century to compensate the energy demand in the present day. As device performance is intimately correlated with the material properties, production of functional energy storage nanomaterials endowed with exceptional physico-chemical properties in view of their particle-size confinement has become critically significant. Low- or moderate-temperature synthetic strategies that are versatile, easily scalable, and efficiently produce size-tuned and efficient materials are essential. In the recent past, combustion-based synthetic process has emerged as one of the promising strategies for developing customized energy storage nanomaterials due to rapid synthesis and ease of preparations in a large scale, etc. In the present review, the advancements in the design and chemistry of these strategies in developing a wide range of high voltage cathode materials for LIBs have been discussed. Among the various combustion techniques, this study will focus mainly on solution combustion, sol-gel based combustion and polyol-based pyro-synthesis. The versatility of these processes to provide tailored particle morphologies and particle sizes at the nanoscale and their effects on the material performance in various applications, particularly in energy storage, is also discussed.

Nowadays, building energy management is more important than ever. Especially, lighting energy used in the building occupies 30% of the whole consumed energy. Therefore, reducing the consumption of lighting energy could bring effective energy saving. As the system configuration, the sum of distance between the window and the light shelf reflector and width of light shelf is set to be 500 mm at maximum. The horizontal width of light shelf is set between 200 mm, the angle of light shelf is set between -90 and 90, and the horizontal distance between the window and the light shelf reflector is set between 0 mm and 300 mm in consideration of sum of width of light shelf. The light shelf system suggested in this study can be used as the basic design data for various design elements in a building.