Cathode materials of metal-ion batteries for low-temperature applications

Energy storage devices have been developed greatly in recent years. Developing forward, they are expected to operate stably in electric vehicles, electric grids, military equipment, and aerospaces in various climates. Unfortunately, these areas require batteries to be repeatedly and periodically exposed to sub-zero temperatures, even extremely low temperatures (-40 degrees C or lower). The low temperature reduces the kinetics of all the activation processes of the batteries, leading to increased impedance and polarization, and loss of battery energy and power, thus restricting their performance. Developing new cathode materials is one of the main strategies to alleviate the low-temperature restrictions. A conventional lithium-ion battery is the most attractive system, which is more adaptive to the practical low-temperature application now. Sodium ion batteries, magnesium-ion batteries, and zinc-ion batteries, which have the advantages of low cost and high safety, are considered potential substitutes for lithium-ion batteries, the electrochemical performance of these batteries at low-temperature has been conducted extensively. This review provides an overview of lithium-ion batteries, sodium-ion batteries, magnesium-ion batteries, and zinc-ion batteries that can work normally in low-temperature environments, with emphasis on various high-energy cathode materials, mainly including polyanionic compounds, layered oxides, spinel oxides, Prussian blue, and Prussian blue analogs. Specifically, we propose how the conventional low-temperature charge-transfer resistance can be overcome. However, these chemistries also present their own unique challenges at low temperatures. This article discusses the advantages and disadvantages of these materials, as well as the main challenges and strategies for applying them to batteries at low temperatures so that the batteries can still discharge efficiently.(c) 2022 Elsevier B.V. All rights reserved

Cathode materials of metal-ion batteries for low-temperature applications

Energy storage devices have been developed greatly in recent years. Developing forward, they are expected to operate stably in electric vehicles, electric grids, military equipment, and aerospaces in various climates. Unfortunately, these areas require batteries to be repeatedly and periodically exposed to sub-zero temperatures, even extremely low temperatures (-40 degrees C or lower). The low temperature reduces the kinetics of all the activation processes of the batteries, leading to increased impedance and polarization, and loss of battery energy and power, thus restricting their performance. Developing new cathode materials is one of the main strategies to alleviate the low-temperature restrictions. A conventional lithium-ion battery is the most attractive system, which is more adaptive to the practical low-temperature application now. Sodium ion batteries, magnesium-ion batteries, and zinc-ion batteries, which have the advantages of low cost and high safety, are considered potential substitutes for lithium-ion batteries, the electrochemical performance of these batteries at low-temperature has been conducted extensively. This review provides an overview of lithium-ion batteries, sodium-ion batteries, magnesium-ion batteries, and zinc-ion batteries that can work normally in low-temperature environments, with emphasis on various high-energy cathode materials, mainly including polyanionic compounds, layered oxides, spinel oxides, Prussian blue, and Prussian blue analogs. Specifically, we propose how the conventional low-temperature charge-transfer resistance can be overcome. However, these chemistries also present their own unique challenges at low temperatures. This article discusses the advantages and disadvantages of these materials, as well as the main challenges and strategies for applying them to batteries at low temperatures so that the batteries can still discharge efficiently.(c) 2022 Elsevier B.V. All rights reserved

Medium-Entropy-Alloy FeCoNi Enables Lithium-Sulfur Batteries with Superb Low-Temperature Performance

Lithium-sulfur battery suffers from sluggish kinetics at low temperatures, resulting in serious polarization and reduced capacity. Here, this work introduces medium-entropy-alloy FeCoNi as catalysts and carbon nanofibers (CNFs) as hosts. FeCoNi nanoparticles are in suit synthesized in cotton-derived CNFs. FeCoNi with atomic-level mixing of each element can effectively modulate lithium polysulfides (LiPSs), multiple components making them promising to catalyze more LiPSs species. The higher configurational entropy endows FeCoNi@CNFs with extraordinary electrochemical activity, corrosion resistance, and mechanical properties. The fractal structure of CNFs provides a large specific surface area, leaving room for volume expansion and Li2S accumulation, facilitating electrolyte wetting. The unique 3D conductive network structure can suppress the shuttle effect by physicochemical adsorption of LiPSs. This work systematically evaluates the performance of the obtained Li2S6/FeCoNi@CNFs electrode. The initial discharge capacity of Li2S6/FeCoNi@CNFs reaches 1670.8 mAh g(-1) at 0.1 C under -20 degrees C. After 100 cycles at 0.2 C, the capacity decreases from 1462.3 to 1250.1 mAh g(-1). Notably, even under -40 degrees C at 0.1 C, the initial discharge capacity of Li2S6/FeCoNi@CNFs still reaches 1202.8 mAh g(-1). After 100 cycles at 0.2 C, the capacity retention rate is 50%. This work has important implications for the development of low-temperature Li-S batteries

A Kinetic and Mechanismic Study of Plasma-Induced Degradation of Monochloropropionic Acids in Water by Means of Anodic Contact Glow Discharge Electrolysis

Decomposition of aqueous monochloropropionic acids (MCPAs) was investigated by means of anodic contact glow discharge electrolysis (CGDE). With the decay of MCPAs, the corresponding total organic carbon (TOC) also decreased smoothly. Furthermore, it was found that chlorine atoms in the MCPAs were released as chloride ions. As the main by-products, oxalic acid and formic acid were detected. The acetic acid (CA), monochloroacetic acid (MCA), and propanedioic acid (PDA) were also detected as the primary intermediates for decomposition of the corresponding MCPAs. The decay of both MCPAs and TOC obeyed the first-order kinetics, respectively. The apparent rate constant for the decay of MCPAs increased with the increase in pKa values of MCPAs, while that for the decay of TOC was substantially unaffected. The reaction pathway involving the successive attack of hydroxyl radical and the carbon chain cleavage were discussed based on the products and kinetics

Medium-Entropy-Alloy FeCoNi Enables Lithium-Sulfur Batteries with Superb Low-Temperature Performance

Lithium-sulfur battery suffers from sluggish kinetics at low temperatures, resulting in serious polarization and reduced capacity. Here, this work introduces medium-entropy-alloy FeCoNi as catalysts and carbon nanofibers (CNFs) as hosts. FeCoNi nanoparticles are in suit synthesized in cotton-derived CNFs. FeCoNi with atomic-level mixing of each element can effectively modulate lithium polysulfides (LiPSs), multiple components making them promising to catalyze more LiPSs species. The higher configurational entropy endows FeCoNi@CNFs with extraordinary electrochemical activity, corrosion resistance, and mechanical properties. The fractal structure of CNFs provides a large specific surface area, leaving room for volume expansion and Li2S accumulation, facilitating electrolyte wetting. The unique 3D conductive network structure can suppress the shuttle effect by physicochemical adsorption of LiPSs. This work systematically evaluates the performance of the obtained Li2S6/FeCoNi@CNFs electrode. The initial discharge capacity of Li2S6/FeCoNi@CNFs reaches 1670.8 mAh g(-1) at 0.1 C under -20 degrees C. After 100 cycles at 0.2 C, the capacity decreases from 1462.3 to 1250.1 mAh g(-1). Notably, even under -40 degrees C at 0.1 C, the initial discharge capacity of Li2S6/FeCoNi@CNFs still reaches 1202.8 mAh g(-1). After 100 cycles at 0.2 C, the capacity retention rate is 50%. This work has important implications for the development of low-temperature Li-S batteries

Biomass-Derived Porous Carbon with a Good Balance between High Specific Surface Area and Mesopore Volume for Supercapacitors

Porous carbon has been one desirable electrode material for supercapacitors, but it is still a challenge to balance the appropriate mesopore volume and a high specific surface area (SSA). Herein, a good balance between a high SSA and mesopore volume in biomass-derived porous carbon is realized by precarbonization of wheat husk under air atmosphere via a chloride salt sealing technique and successive KOH activation. Due to the role of molten salt generating mesopores in the precarbonized product, which can further serve as the active sites for the KOH activation to form micropores in the final carbon material, the mesopore–micropore structure of the porous carbon can be tuned by changing the precarbonization temperature. The appropriate amount of mesopores can provide more expressways for ion transfer to accelerate the transport kinetics of diffusion-controlled processes in the micropores. A high SSA can supply abundant sites for charge storage. Therefore, the porous carbon with a good balance between the SSA and mesopores exhibits a specific gravimetric capacitance of 402 F g−1 at 1.0 A g−1 in a three-electrode system. In a two-electrode symmetrical supercapacitor, the biomass-derived porous carbon also delivers a high specific gravimetric capacitance of 346 F g−1 at 1.0 A g−1 and a good cycling stability, retaining 98.59% of the initial capacitance after 30,000 cycles at 5.0 A−1. This work has fundamental merits for enhancing the electrochemical performance of the biomass-derived porous carbon by optimizing the SSA and pore structures

Fabrications and Na+ Storage Characteristics of Nitrogen-doped Biomass-derived Carbon Materials

The biomass-derived carbon materials were successfully fabricated by precursor mixtures of eggplants, urea and CaCl2. It is promisingly observed that controlling the mixing ratios of eggplants, urea and CaCl2 can regulate the structures of fabricated carbon materials. On the basis of investigations about correlations between structures and Na+ storage capacity, it is verified that weight ratio of eggplants : urea : CaCl2 = 1 : 2 : 2 is optimal to fabricate the carbon materials, which have the suitable porous structures and specific surface area to store Na+. For instance, the fabricated carbon materials show the Na+ storage capacity is 200.8 mAh/g at 0.1 A/g, after being carried out the charge-discharge 500 times. Meanwhile, the same materials also display the impressive long cycling performance. When cycling the charge-discharge 1000 times at 2.0 A/g, the fabricated carbon materials still manifest the Na+ storage capacity at 137.8 mAh/g

Study on Na⁺ Storage Mechanisms of Carbon Black (Supporting Information)

To better understand the Na+ storage mechanism of general carbon materials, the suitable choice of study model is really pivotal. Carbon black (CB) attracts us to consider that it is a suitable model to study the Na+ storage mechanism because CB is an extremely popular industry product, and a lot of organic groups exist on its surface. After detailed electrochemical evaluations, it is surprisingly observed that the CB shows the tremendous Na+ storage capacity. For instance, Na+ storage capacity is 103.3 mAh g−1, after the discharge-charge process was performed 10000 cycles at 5.0 A g−1. Additionally, the CB still shows the storage capacity at 90 mAh g−1, during 10000 cycles at 10.0 A g−1. The storage mechanism was studied from two aspects which are structural conversions and surface effect. After performing the XRD, XPS, BET measurements and DFT and GITT calculations, it is aware of that the synergistic effect of capacitive effect brought by the –C=O of ester groups on the CB surface and structural conversions of CB contribute to the Na+ storage capacity. Our analysis results about storage mechanism of CB are capable to provide a beneficial reference for unfolding the carbon materials having storage capacity for Na+.</div