•Organosolv is recognized as an emerging pretreatment because its inherent advantages.•Organosolv pretreatment fractionates biomass into its components with high-purity.•Organic solvent is easy ...recovery and reuse during organosolv pretreatment.•Previous works on organosolv pretreatment of biomass were updated and extended.•Perspectives were given to implementation of proper organosolv pretreatment.
Lignocellulosic biomass represents the largest potential volume and lowest cost for biofuel and biochemical production. Pretreatment is an essential component of biomass conversion process, affecting a majority of downstream processes, including enzymatic hydrolysis, fermentation, and final product separation. Organic solvent pretreatment is recognized as an emerging way ahead because of its inherent advantages, such as the ability to fractionate lignocellulosic biomass into cellulose, lignin, and hemicellulose components with high purity, as well as easy solvent recovery and solvent reuse. Objectives of this review were to update and extend previous works on pretreatment of lignocellulosic biomass for biofuels and biochemicals using organic solvents, especially on ethanol, methanol, ethylene glycol, glycerol, acetic acid, and formic acid. Perspectives and recommendations were given to fully describe implementation of proper organic solvent pretreatment for future research.
This paper presents a sensor-guided gait-synchronization system to help potential unilateral knee-injured people walk normally with a weight-supported lower-extremity-exoskeleton (LEE). This relieves ...the body weight loading on the knee-injured leg and synchronizes its motion with that of the healthy leg during the swing phase of walking. The sensor-guided gait-synchronization system is integrated with a body sensor network designed to sense the motion/gait of the healthy leg. Guided by the measured joint-angle trajectories, the motorized hip joint lifts the links during walking and synchronizes the knee-injured gait with the healthy gait by a half-cycle delay. The effectiveness of the LEE is illustrated experimentally. We compare the measured joint-angle trajectories between the healthy and knee-injured legs, the simulated knee forces, and the human-exoskeleton interaction forces. The results indicate that the motorized hip-controlled LEE can synchronize the motion/gait of the combined body-weight-supported LEE and injured leg with that of the healthy leg.
Herein, we report a synthesis of highly crumpled nitrogen-doped graphene sheets with ultrahigh pore volume (5.4 cm3/g) via a simple thermally induced expansion strategy in absence of any templates. ...The wrinkled graphene sheets are interwoven rather than stacked, enabling rich nitrogen-containing active sites. Benefiting from the unique pore structure and nitrogen-doping induced strong polysulfide adsorption ability, lithium–sulfur battery cells using these wrinkled graphene sheets as both sulfur host and interlayer achieved a high capacity of ∼1000 mAh/g and exceptional cycling stability even at high sulfur content (≥80 wt %) and sulfur loading (5 mg sulfur/cm2). The high specific capacity together with the high sulfur loading push the areal capacity of sulfur cathodes to ∼5 mAh/cm2, which is outstanding compared to other recently developed sulfur cathodes and ideal for practical applications.
► Infrared techniques are fast, accurate, and low-cost for biomass analysis. ► A comparison of infrared techniques and chemical method is made. ► Chemometric analaysis provides prediction model for ...composition analysis.
Current wet chemical methods for biomass composition analysis using two-step sulfuric acid hydrolysis are time-consuming, labor-intensive, and unable to provide structural information about biomass. Infrared techniques provide fast, low-cost analysis, are non-destructive, and have shown promising results. Chemometric analysis has allowed researchers to perform qualitative and quantitative study of biomass with both near-infrared and mid-infrared spectroscopy. This review summarizes the progress and applications of infrared techniques in biomass study, and compares the infrared and the wet chemical methods for composition analysis. In addition to reviewing recent studies of biomass structure and composition, we also discuss the progress and prospects for the applications of infrared techniques.
The interfacial instability of the lithium-metal anode and shuttling of lithium polysulfides in lithium-sulfur (Li-S) batteries hinder the commercial application. Herein, we report a bifunctional ...electrolyte additive, i.e., 1,3,5-benzenetrithiol (BTT), which is used to construct solid-electrolyte interfaces (SEIs) on both electrodes from in situ organothiol transformation. BTT reacts with lithium metal to form lithium 1,3,5-benzenetrithiolate depositing on the anode surface, enabling reversible lithium deposition/stripping. BTT also reacts with sulfur to form an oligomer/polymer SEI covering the cathode surface, reducing the dissolution and shuttling of lithium polysulfides. The Li-S cell with BTT delivers a specific discharge capacity of 1,239 mAh g
(based on sulfur), and high cycling stability of over 300 cycles at 1C rate. A Li-S pouch cell with BTT is also evaluated to prove the concept. This study constructs an ingenious interface reaction based on bond chemistry, aiming to solve the inherent problems of Li-S batteries.
The lithium (Li) metal anode suffers severe interfacial instability from its high reactivity toward liquid electrolytes, especially carbonate-based electrolytes, resulting in poor electrochemical ...performance of batteries that use 4 V high-capacity cathodes. We report a new skin-grafting strategy that stabilizes the Li metal–liquid electrolyte interface by coating the Li metal surface with poly((N-2,2-dimethyl-1,3-dioxolane-4-methyl)-5-norbornene-exo-2,3-dicarboximide), a chemically and electrochemically active polymer layer. This layer, composed of cyclic ether groups with a stiff polycyclic main chain, serves as a grafted polymer skin on the Li metal anode not only to incorporate ether-based polymeric components into the solid-electrolyte interphase (SEI) but also to accommodate Li deposition/dissolution under the skin in a dendrite/moss-free manner. Consequently, a Li-metal battery employing a Li metal anode with the grafted skin paired with LiNi0.5Co0.2Mn0.3O2 cathode has a 90.0% capacity retention after 400 charge/discharge cycles and a capacity of 1.2 mAh/cm2 in a carbonate-based electrolyte. This proof-of-concept study provides a new direction for regulating the interfacial chemistry of Li metal anodes and for enabling high-performance Li-metal batteries.
Chitosan-based hydrogel has been widely used in the field of tissue engineering due to its favorable biocompatibility and good biodegradability. However, this kind of hydrogel generally exhibits poor ...mechanical stability, which greatly limits its application in the field of 3D bioprinting. In this study, we provided a hybrid bioink created from photocurable chitosan and acrylamide (AM) for digital light processing (DLP) based 3D bioprinting in tissue engineering applications. This hybrid bioink was facilely prepared by combining AM and chitosan modified with methacryloyl groups (CHIMA). The gelling point of the hybrid pre-hydrogel bioink was greatly dependent on the photoinitiators. Both the mechanical properties and cytocompatibility of the hydrogel formed by the bioink can be modulated by varying the AM contents. The hybridization of natural CHIMA and synthetic AM enables the hybrid hydrogels with desirable biological activity and mechanical properties. Utilizing the DLP based 3D printing, this hybrid bioink can be processed into complex 3D hydrogel constructs with high-strength and good biocompatibility. Therefore, the photocurable hybrid bioink composed of CHIMA and AM in proper proportion is well suitable for use in DLP based 3D bioprinting, which would play a promising role in constructing tissues and organs in the future.
Display omitted
•A photocurable hybrid bioink composed of chitosan and AM is provided for DLP bioprinting.•Using DLP, the hybrid bioink can be processed into complex 3D hydrogel constructs.•The printed constructs are endowed with high-strength and good biocompatibility.
Lithium metal is a promising anode candidate for the next-generation rechargeable battery due to its highest specific capacity (3860 mA h g
) and lowest potential, but low Coulombic efficiency and ...formation of lithium dendrites hinder its practical application. Here, we report a self-formed flexible hybrid solid-electrolyte interphase layer through co-deposition of organosulfides/organopolysulfides and inorganic lithium salts using sulfur-containing polymers as an additive in the electrolyte. The organosulfides/organopolysulfides serve as "plasticizer" in the solid-electrolyte interphase layer to improve its mechanical flexibility and toughness. The as-formed robust solid-electrolyte interphase layers enable dendrite-free lithium deposition and significantly improve Coulombic efficiency (99% over 400 cycles at a current density of 2 mA cm
). A lithium-sulfur battery based on this strategy exhibits long cycling life (1000 cycles) and good capacity retention. This study reveals an avenue to effectively fabricate stable solid-electrolyte interphase layer for solving the issues associated with lithium metal anodes.The practical application of lithium metal anodes suffers from the poor Coulombic efficiency and growth of lithium dendrites. Here, the authors report an approach to enable the self-formation of stable and flexible solid-electrolyte interphase layers which serve to address both issues.
In spite of recent progress, there is still a lack of reliable organic electrodes for Li storage with high comprehensive performance, especially in terms of long‐term cycling stability. Herein, we ...report an ideal polymer electrode based on anthraquinone, namely, polyanthraquinone (PAQ), or specifically, poly(1,4‐anthraquinone) (P14AQ) and poly(1,5‐anthraquinone) (P15AQ). As a lithium‐storage cathode, P14AQ showed exceptional performance, including reversible capacity almost equal to the theoretical value (260 mA h g−1; >257 mA h g−1 for AQ), a very small voltage gap between the charge and discharge curves (2.18–2.14=0.04 V), stable cycling performance (99.4 % capacity retention after 1000 cycles), and fast‐discharge/charge ability (release of 69 % of the low‐rate capacity or 64 % of the energy in just 2 min). Exploration of the structure–performance relationship between P14AQ and related materials also provided us with deeper understanding for the design of organic electrodes.
No compromises! An ideal polymer electrode based on anthraquinone, poly(1,4‐anthraquinone) (P14AQ), was applied as a cathode for rechargeable lithium batteries (see picture). Unrivaled by other organic electrodes, it showed exceptional performance, including stable cycling (99.4 % capacity retention after 1000 cycles) and fast discharge/charge ability (releasing 69 % of the low‐rate capacity or 64 % of the energy in just 2 min).
PDF
