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Pore structure properties such as specific surface area, pore volume, and pore size distribution are important considerations when using nanoporous carbons as electrochemical energy storage and H2storage materials. In this work, the Quenched Solid Density Functional Theory (QSDFT) analysis is employed to study the nanopore structure of hierarchical porous carbon (HPC) materials derived from bamboo chopsticks (BCS) by adopting a few-step chemical activation method. The effect of carbonization temperature (600–800 °C) and inorganic activator ratio on the surface chemistry and properties of HPC materials are investigated along with the way this influences the energy storage and H2storage performances. The as-prepared materials exhibit high surface area (1439–1940 m2 g−1) and porosity, which is achieved even with a low KOH:BCS ratio. The supercapacitor (SC) HPC material processed at 800 °C and a KOH:BCS of 2:1, showed a good capacitive performance of 360 F g−1at a current density of 0.5 A g−1and exhibited a superior rate characteristic along with excellent electrochemical stability. A symmetrical SC reached a specific energy of over 75.3 Wh kg−1and a specific power of 375 W kg−1in an organic electrolyte. Furthermore, pouch cell type SC devices are fabricated to light LEDs. The hydrogen uptake of all the HPC samples is above 2 wt% (at 77 K and 1 bar) with the highest being 2.3 wt% for the sample processed at 700 °C due to its higher micropore volume. This study proposes a feasible low-cost method to convert waste biomass and exploit the desired hierarchical porous carbon material for multifunctional storage applications.

In reactive bimetallic compounds such as Ni–Al multilayers, desirable thermo-kinetic properties upon ignition require simultaneously controlled geometric microstructure and material composition. This article establishes fundamental dynamical models of plastic deformation and material diffusion in ball milling processing of particulates from Ni and Al powders, for the purpose of designing and implementing feedback control strategies for process control. The role of heat dissipation from plastic yield and friction slip in affecting compressibility and diffusivity of the material is elucidated. The different sensitivity of compressibility and diffusivity to thermal power is exploited by introducing multivariable control of both bilayer thickness and penetration depth simultaneously, using a real-time computational model as an observer with adaptation informed by infrared measurements of external vial temperature. The proposed control scheme is tested on a laboratory low-energy ball milling system and demonstrated to effectively modulate power intensity and process duration to obtain the desired microstructure and material composition.

The efficient storage of energy combined with a minimum carbon footprint is still considered one of the major challenges towards the transition to a progressive, sustainable and environmental friendly society on a global scale. The energy storage in pure chemical form using gas carriers with high heating values, including H2and CH4, as well as via electrochemical means using state-of-the-art devices, such as batteries or supercapacitors, are two of the most attractive alternatives for the combustion of finite, carbon-rich and environmentally harmful fossil fuels, such as diesel and gasoline. A few-step, reproducible and scalable method is presented in this study for the preparation of an ultra-microporous (average pore size around 0.6nm) activated carbon cloth (ACC) with large specific area (> 1200m2/g) and pore volume (~ 0.5cm3/g) upon combining chemical impregnation, carbonization and CO2activation of a low-cost cellulose-based polymeric fabric. The ACC material shows a versatile character towards three different applications, including H2storage via cryo-adsorption, separation of energy-dense CO2/CH4mixtures via selective adsorption and electrochemical energy storage using supercapacitor technology. Fully reversible H2uptake capacities in excess of 3.1wt% at 77K and ~ 72bar along with a significant heat of adsorption value of up to 8.4kJ/mol for low surface coverage have been found. Upon incorporation of low-pressure sorption data in the ideal adsorbed solution theory model, the ACC is predicted to selectively adsorb about 4.5 times more CO2than CH4in ambient conditions and thus represents an appealing adsorbent for the purification of such gaseous mixtures. Finally, an electric double-layer capacitor device was assembled and tested for its electrochemical performance, constructed of binder-free and flexible ACC electrodes and aqueous CsCl electrolyte. The full-cell exhibits a gravimetric capacitance of ~ 121F/g for a specific current of 0.02A/g, which relative to the ACC's specific area, is superior to commercially available activated carbons. A capacitance retention of more than 97% was observed after 10,000 charging/discharging cycles, thus indicating the ACC's suitability for demanding and high-performance energy storage on a commercial scale. The enhanced performance in all tested applications seems to be attributed to the mean ultra-micropore size of the ACC material instead of the available specific area and/or pore volume.