Specific Discharge Capacity Research Articles

VO2/VS4 heterostructures structure–modified 3D reduced graphene oxide aerogel as an advanced host for lithium–sulfur batteries

Lithium–sulfur batteries face challenges including volume expansion, slow reaction kinetics, and shuttle effects. To overcome these limitations, we utilized a combination of vanadium–based heterostructures and conductive porous reduced graphene oxide aerogels to improve charge transfer kinetics. The researchers synthesised vanadium–based reduced graphene oxide aerogels (VO2/VS4@RGO) via tube furnace calcination and a one–step hydrothermal method. Vanadium–based heterostructures were electrostatically adsorbed onto the surface of three–dimensional reduced graphene oxide aerogels. The fibrous structure of VO2/VS4 promoted charge transfer, while the high conductivity of VS bonds lowered the surface reaction barrier. The VO2/VS4@RGO–3/S cathode exhibited outstanding cycling stability at a high discharge rate of 2C, demonstrating an initial discharge specific capacity of 771.94 mAh g−1 and an average decay rate of 0.071 % after 700 cycles. It also maintained excellent electrochemical performance under high sulfur loading.

Investigation on Al3+ ion storage in Bi2MoO6 and Bi2WO6 for rechargeable aqueous aluminum-ion battery

Reversible and stable electrochemical Al3+ ion storage process defines the functioning of a rechargeable aluminum-ion battery. Herein, we illustrate the electrochemistry of Bi2MoO6 and Bi2WO6 for Al3+ ion storage in aqueous electrolyte. It was found that the electrochemical characteristics are quite dependent on the nature of the electrolyte. While the charge-discharge profiles are almost identical for both Bi2MoO6 and Bi2WO6, it is to be noted that Bi2WO6 exhibits better electrochemical long-term stability and severe capacity decline is noticeable for Bi2MoO6. The specific discharge capacity is 94 mAhg−1 at a current density of 1 Ag−1 over 50 cycles for Bi2WO6 in an optimized AlCl3 aqueous electrolyte. By adopting an optimized current collector, the specific capacity could be significantly enhanced to above 200 mAhg−1 at a current density of 1 Ag−1. A mechanistic study conducted through ex-situ XRD, XPS, Raman, FTIR, UV–Visible, FESEM and HRTEM reveals probable transformation of Bi2WO6 to BiOCl during the electrochemical process.

Advanced-design cross-linked binder enables high-performance silicon-based anodes through in-situ crosslinking based on sodium carboxymethyl cellulose and poly-lysine

Practical employment of silicon (Si) electrodes in lithium-ion batteries (LIBs) is limited due to the severe volume changes suffered during charging-discharging process, causing serious capacity fading. Here, a composite polymer (CP-10) containing sodium carboxymethyl cellulose (CMC-Na) and poly-lysine (PL) is proposed for the binder of Si-based anodes, and a multifunctional strategy of “in-situ crosslinking” is achieved to alleviate the severe capacity degradation effectively. A cross-linked three-dimensional (3D) network is established through the strong hydrogen bonding interaction and reversible electrostatic interactions within CP-10, offering favorable mechanical tolerance for the extreme volume expansion of Si. Moreover, hydrogen bonding interaction along with ion-dipole interaction formed between CP-10 and Si surface enhance the bonding capability of Si-based anodes, promoting the maintenance of anodes' integrity. Consequently, over 800 cycles are achieved for the Si@CP-10 at 0.5C while maintaining a fixed discharge specific capacity of 1000 mAh g−1. Moreover, the Si/C@CP-10 can stably operate over 500 cycles with a capacity retention of 77.12 % at 1C. The prolonged cycling lifetime of Si/C and Si anodes suggests great potential for this strategy in promoting the implementation of high-capacity LIBs.

Nitrogen-doped hollow carbon sphere composite Mn3O4 as an advanced host for lithium-sulfur battery

As the most promising advanced energy storage system, lithium-sulfur batteries (LSBs) are highly favored by the researchers because of their advantages of high energy density (2500 W h kg−1), low cost and non-pollution. However, the low conductivity, volume expansion of sulfur, and shuttle effect are still the great hindrance to the practical application of LSBs. Herein, the above problems can be addressed through the following strategies: (1) Hollow carbon microspheres with high specific surface area were constructed as sulfur hosts to increase sulfur loading while also being able to enhance the physical adsorption of polysulfides; (2) the loading of Mn3O4 particles on the basis of hollow carbon microspheres facilitates the capture and adsorption of polysulfides; (3) the hollow carbon sphere structure as a conductive network can provide more pathways for rapid electrical/ionic transport and also accelerate electrolyte wetting. Moreover, the thinner shell of hollow carbon microsphere is conducive to ion diffusion and speed up the reaction rate. Thus, the NHCS/Mn3O4/S composites exhibit a high discharge specific capacity of 1010.3 mAh g−1 at first and still maintained a reversible capacity of 269.2 mAh g−1 after 500 cycles. This work presents a facile sustainable and efficient synergistic strategy for the development of advanced LSBs.

Surface-to-bulk synergistic modification enables stable interface of Ni-rich oxide cathode for all-solid-state lithium batteries

All-solid-state lithium batteries (ASSLBs) are supposed to a highly forward-looking battery technology by reason of their conspicuous energy density and excellent safety. Ni-rich layered oxide cathodes have been extensively studied in ASSLB systems with sulfide electrolytes owing to their high voltage and preeminent specific capacity. However, the electrochemical performance of ASSLBs is severely degraded due to the interfacial physical contact failure, space charge layer effect, and chemical/electrochemical side reactions between sulfide electrolytes and Ni-rich oxide cathodes. In this work, the surface of LiNi0.92Co0.04Mn0.04O2 (NCM92) is coated with a nano-level CeO2 buffer layer and is simultaneously doped with Ce element (NCM92–1%Ce) by one-step wet chemical method. Ce doping is beneficial for maintaining structural stability and suppressing irreversible phase transition. The CeO2 buffer layer can efficaciously avoid the oxidation and decomposition phenomenon at the interface between NCM92 and sulfide electrolyte. As expected, NCM92–1%Ce cathode shows the discharge specific capacity of 141.46 mAh g−1 after 80 cycles at 0.2C with 79.32% capacity retention rate, which is much higher than that of the unmodified NCM92 cathode. The results indicate that the surface-to-bulk synergistic modification strategy can successfully improve the structure toughness and interface stability of Ni-rich oxide cathode for ASSLBs with sulfide electrolytes.

Elucidating the Impact of Li3InCl6-Coated LiNi0.8Co0.15Al0.05O2 on the Electro-Chemo-Mechanics of Li6PS5Cl-Based Solid-State Batteries.

Li6PS5Cl has attracted significant attention due to its high Li-ion conductivity and processability, facilitating large-scale solid-state battery applications. However, when paired with high-voltage cathodes, it experiences adverse side reactions. Li3InCl6 (LIC), known for its higher stability at high voltages and moderate Li-ion conductivity, is considered a catholyte to address the limitations of Li6PS5Cl. To extend the stability of Li6PS5Cl toward LiNi0.8Co0.15Al0.05O2 (NCA), we applied nanocrystalline LIC as a 180 nm-thick protective coating in a core-shell-like fashion (LIC@NCA) via mechanofusion. Solid-state batteries with LIC@NCA allow an initial discharge specific capacity of 148 mA h/g at 0.1C and 80% capacity retention for 200 cycles at 0.2C with a cutoff voltage of 4.2 V (vs Li/Li+), while cells without LIC coating suffers from low initial discharge capacity and poor retention. Using a wide spectrum of advanced characterization techniques, such as operando XRD, XPS, FIB-SEM, and TOF-SIMS, we reveal that the superior performance of solid-state batteries employing LIC@NCA is related to the suppression of detrimental interfacial reactions of NCA with Li6PS5Cl, delamination, and particle cracking compared to uncoated NCA.

Add an Extra Layer to Bring Lithium‐Ions Out of Disorder for Longevity of the Solid Full Batteries

AbstractIn the current era of rapid development in the new energy vehicle industry, graphite (Gr) has gained significant attention as the primary anode material for commercial lithium‐ion batteries due to its exceptional reversibility in lithium‐ion insertion/extraction and abundant availability. In this study, a multifunctional ferroelectric Bi12TiO20@C (BIT@C) modified interlayer between Gr and polymer electrolyte (PE) is fabricated. This approach established a channel and homogeneous ion‐conducting network that facilitated lithium‐ion intercalation into Gr at the interface while suppressing erratic lithium precipitation, thereby stabilizing the structure of Gr. The uniform electric field generated by BIT intercalation enabled homogeneous intercalation/deintercalation of lithium ions, effectively preventing the structural collapse of the Gr anode. Assembled LIBs exhibited reduced polarization and enhanced electrochemical properties attributed to facile charge transfer at the interface. The results revealed that Gr│carbon‐BIT@C‐lithium bistrifluoromethane sulfonimide (LiTFSI)/silicon dioxide (SiO2)/poly allyl acetoacetate (PAAA)/poly(vinylidene fluoride‐hexafluoropropylene) (P(VDF‐HFP))/polyvinylidene fluoride (PVDF)│LiFePO4 (LFP) batteries achieved an initial discharge specific capacity of 120.4 mAh g−1 with stable performance over 1200 cycles at 2 C and room temperature (RT), maintaining a Coulombic efficiency of 99.5% after 1200 cycles. The ferroelectric‐modified interface addressed challenges associated with ion transport at the electrode‐electrolyte interface.

Construction of CeO2/Co/CNT electrocatalyst with adsorption-catalytic synergistic effect for the suppression of the shuttle effect in lithium sulfur batteries

Lithium‑sulfur batteries are recognized as a strong candidate for the next generation of high capacity density batteries. However, the shuttle effect of soluble polysulfide intermediates during the charging and discharging process of lithium‑sulfur batteries leads to a rapid decrease in their electrochemical performance, thus limiting their practical applicability. In this study, the rare earth element cerium (Ce) was introduced into a bimetallic electrocatalyst to modify the separator in order to inhibit the shuttle effect for soluble polysulfide intermediates in lithium‑sulfur batteries. The CeO2/Co bimetallic electrocatalyst composite with in situ-grown carbon nanotubes (CeO2/Co/CNT) was obtained by a simple single-step high-temperature carbonization process. The strong polarity of CeO2 in CeO2/Co/CNT could trap soluble polysulfide intermediates onto the composite surface, synergizing with Co to further enhance the catalytic efficiency of soluble polysulfide intermediates into insoluble Li2S. Simultaneously, CNTs in CeO2/Co/CNT provided fast Li+ and electron transfer channels for the efficient catalytic conversion of soluble polysulfide intermediate. The initial discharge specific capacity of lithium‑sulfur batteries assembly by using CeO2/Co/CNT modified separator presented an initial discharge specific capacity of 1377.05 mAh g−1 at 0.1 C, and 676.8 mAh g−1 after 200 cycles at 1 C, demonstrating a significant performance improvement compared to blank control battery.

Novel binary regulated silicon-carbon materials as high-performance anodes for lithium-ion batteries

The massive volume dilation, unsteady solid electrolyte interphase, and weak conductivity about Si have failed to bring it to practical applications, although its potential capacity is up to 4200 mAh g−1. For solving these problems, novel binary regulated silicon–carbon materials (Si/BPC) were done by a sol–gel procedure combined with single carbonization. Analytical techniques were systematically utilized to examine the effects of element doping at several gradients on morphology, structure and electrochemical properties of composites, thus the optimal content was identified. Si/BPC preserves a discharge specific capacity of 1021.6 mAh g−1 with a coulomb efficiency of 99.27% after 180 cycles at 1000 mA g−1, within the upgrade than single-doped and undoped. In rate test, it has a specific capacity of 1003.2 mAh g−1 at a high current density of 5000 mA g−1, quickly back towards 2838.6 mAh g−1 at 200 mA g−1. The inclusion of B and P elements is linked to the electrochemical characteristics. In the co-doped carbon layers, the synergistic impact of doping B and P accelerates the diffusion kinetics of lithium ions, boosts diffusion rate of Li+, offers low electrochemical impedance (45.75 Ω). This brings more defects to provide transport carriers and induces a substantial amount of electrochemically active sites, which fosters the storage of Li+, thus making silicon material electrochemically more active and potential.

Effect of polypyrrole-derived N-doped carbon coating on the sodium storage properties of NiCo2S4 synthesized by recycling discarded mobile phone batteries

NiCo2S4 with a spherical spinel structure was innovatively synthesized from discarded mobile phone batteries using a simple hydrothermal method, and the surface was coated with N-doped carbon to form NiCo2S4@NC. The products were used as anode materials of sodium-ion batteries to study the effect of the N-doped carbon layer on the electrochemical properties, structure and morphology. The results of XRD, FESEM and TEM revealed that the N-doped carbon layer derived by carbonizing polypyrrole had a minimal effect on the structure and morphology of NiCo2S4, but was coated on the surface of NiCo2S4 with different thicknesses to adjust the electrochemical performance. The presence of N-doped carbon in NiCo2S4@NC was confirmed by Raman spectroscopy. The mesoporous structure of NiCo2S4 and NiCo2S4@NC was corroborated by N2 adsorption-desorption isotherm analysis, and the optimal specific surface area and pore size were 23.14 cm2/g and 18.0 nm, respectively. X-ray photoelectron spectroscopy indicated that Co2+/Co3+ and Ni2+/Ni3+ coexist in the spinel NiCo2S4@NC50 synthesized upon adding 50 μL of pyrrole monomer. NiCo2S4@NC50 outperformed other products in terms of its electrochemical properties, where its initial discharge specific capacity under the current density of 0.1 A g−1 was 1099.6 mA h g−1 and the specific capacity following 100 cycles reached 327.5 mA h g−1. NiCo2S4@NC50 exhibited an optimal electrochemical performance and demonstrated a competent approach toward recycling discarded mobile phone batteries and building electrodes with high performance for use in energy equipment.

Preparation of Expanded Graphite-VO2 Composite Cathode Material and Performance in Aqueous Zinc-Ion Batteries.

Due to safety problems caused by the use of organic electrolytes in lithium-ion batteries and the high production cost brought by the limited lithium resources, water-based zinc-ion batteries have become a new research focus in the field of energy storage due to their low production cost, safety, efficiency, and environmental friendliness. This paper focused on vanadium dioxide and expanded graphite (EG) composite cathode materials. Given the cycling problem caused by the structural fragility of vanadium dioxide in zinc-ion batteries, the feasibility of preparing a new composite material is explored. The EG/VO2 composites were prepared by a simple hydrothermal method, and compared with the aqueous zinc-ion batteries assembled with a single type of VO2 under the same conditions, the electrode materials composited with high-purity sulfur-free expanded graphite showed more excellent capacity, cycling performance, and multiplicity performance, and the EG/VO2 composites possessed a high discharge ratio of 345 mAh g-1 at 0.1 A g-1, and the Coulombic efficiency was close to 100%. The EG/VO2 composite has a high specific discharge capacity of 345 mAh g-1 at 0.1 A g-1 with a Coulombic efficiency close to 100%, a capacity retention of 77% after 100 cycles, and 277.8 mAh g-1 with a capacity retention of 78% at a 20-fold increase in current density. The long cycle test data demonstrated that the composite with expanded graphite effectively improved the cycling performance of vanadium-based materials, and the composite maintained a stable Coulombic efficiency of 100% at a high current density of 2 A/g and still maintained a specific capacity of 108.9 mAh/g after 2000 cycles.

Constructing heterojunction-induced oxygen vacancies of N-doped carbon-encapsulated Sn/SnOx microplates for boosting lithium storage capability

Heterogeneous Sn/SnOx@N-doped carbon (Sn/SnOx@NC) microplates with oxygen vacancies evolved from plate-like SnO powders are successfully fabricated, in which SnO powders are converted into Sn, SnO2, and Sn2O3 phases by rationally sintering and are perfectly in situ encapsulated by polyaniline-derived NC layer. By elaborately constructing the particular structure, high discharge specific capacity of 730.4 mAh/g and capacity retention ratio of 98.3 % after 110 cycles at 0.1 A/g are realized for optimal Sn/SnOx@NC composite electrode. Benefiting from enhanced electronic conductivity and Li+ ions diffusion kinetics, the assembled cell delivers reversible discharge specific capacity of 487.3 mAh/g at 1.0 A/g after 500 cycles. First principles calculation and in/ex situ characterization reveal that in situ formed heterostructure with oxygen vacancies and NC layer synergistically improve interfacial charge transfer and reaction reversibility to promote lithium storage capability. Therefore, fabricating Sn/SnOx@NC microplates may provide a practical strategy to design heterogeneous and oxygen-deficient Sn-based anode materials for high-performance lithium-ion batteries.

Limited Domain SnSb@N-PC Composite Material as a High-Performance Anode for Sodium Ion Batteries

Anode materials have a vital influence on the performance of sodium ion batteries. In this paper, SnSb nanoparticles were distributed uniformly in N-doped three-dimensional porous carbon (SnSb@N-PC), which effectively avoided the agglomeration of alloy nanoparticles and greatly improved the capacity retention rate of SnSb@N-PC. At the same time, the porous carbon substrate brings higher conductivity, larger specific surface area, and more sodium storage sites, which makes the material obtain excellent sodium storage properties. The first discharge-specific capacity of SnSb@N-PC was 846.3 mAh g−1 at the current density of 0.1 A g−1, and the specific capacity remained at 483 mAh g−1 after 100 cycles. Meanwhile, the specific capacity of SnSb@N-PC was kept at 323 mAh g−1 after 400 cycles at a high current density of 1.5 A g−1, which indicated that the recombination of SnSb with porous carbon played a key role in the electrochemical performance of SnSb. The contribution of capacitance contrast capacity was able to reach more than 90% by the cyclic voltammetry (CV) test at high sweep speed, and larger Na+ diffusivity was obtained by the constant current intermittent titration technique (GITT) test, which explains the good rate performance of SnSb@N-PC.

Constructing low-cost stable zinc-ion batteries with sodium-rich monoclinic manganese hexacyanoferrate cathode

Manganese-based Prussian blue analogues are ideal candidate cathode materials for constructing high-voltage zinc-ion batteries. However, challenges have persisted in realizing envisioned highly stable electrochemical cycling systems due to manganese dissolution under aqueous conditions and self-corrosion of zinc metal anodes. Considering practical application demands and cost-effectiveness, non-aqueous organic zinc-ion batteries have shown significant development potential by avoiding interference from active hydrogen and offering a stable wide voltage window. Herein, a sodium-rich monoclinic structured manganese hexacyanoferrate (m-MnHCF) was synthesized via a simple coprecipitation method, achieving a stable high-voltage zinc-ion battery energy storage system in a diluted 0.2 M Zn(CF3SO3)2 electrolyte in acetonitrile, a non-protonic polar solvent. The battery exhibited a discharge specific capacity of 77 mAh g−1 at the current density of 1 A g−1 after 620 cycles. Furthermore, by circumventing interference from active hydrogen, a cost-advantaged zinc powder anode (Zn-P) was successfully introduced into the energy storage system. Assembled Zn-P||m-MnHCF cells exhibited stable cycling for 100 cycles at a current density of 0.5 A g−1 with close to 100 % coulombic efficiency, showcasing limitless possibilities for the future, as demonstrated by illuminated LED arrays.

Fluorine-Doped Li7La3Zr2O12 Fiber-Based Composite Electrolyte for Solid-State Lithium Batteries with Enhanced Electrochemical Performance.

Garnet-based electrolytes with high ionic conductivity and excellent stability against lithium metal anodes are promising for commercial applications in solid-state lithium batteries (SSLBs). However, the further development of SSLBs is inhibited by issues such as low ionic conductivity and uncontrolled lithium dendrite growth. Herein, we report the synthesis of fluorine-doped Li7La3Zr2O12 (LLZO-F0.2) fibers by electrospinning and the subsequent calcination at high temperatures. The solid composite electrolyte with LLZO-F0.2 exhibits an ionic conductivity of 5.37 × 10-4 S cm-1 and a high lithium-ion transference number of 0.61 at room temperature. Meanwhile, it exhibits lower resistance and more uniform lithium metal stripping and deposition in symmetric cells. The full cell with LiFePO4 cathode exhibits excellent rate capability and cycling stability for 800 cycles at 0.5 C with a discharge specific capacity retention of 97.7%. This fluorine-doped fibrous garnet-type electrolyte provides a viable option for preparing high-performance SSLBs.

Enhancing the cycling stability of full-concentration-gradient Ni-rich layered cathodes via in-situ Zr doping

Full-concentration-gradient (FCG) Ni-rich layered cathodes suffers from severe structural deterioration caused by the high-Ni content in the cores of the particles. Herein, an in-situ doping strategy is proposed to remove the structural deterioration in the cores of the particles, and a Zr-doped FCG LiNi0.80-xZrxCo0.05Mn0.15O2 (FNCMZ) cathode is successfully prepared. In-situ doping achieved a gradient distribution of Zr inside the particles, and induced the Li+/Ni2+mixing into an order structure. The order structure and Zr–O strong bonds reduced the degree of lattice contraction in the cores of the particles during the H2–H3 phase transition. Density functional theory calculations further proved that Zr doping and the order structure improved the electronic conductivity and structural stability of the cathodes. The improvement of structural stability and ion/electron migration environment enhanced the cycling stability and thermal stability of the FCG cathodes. Therefore, The FNCMZ0.2 cathode (doped with 0.2 mol% Zr) exhibited a high initial discharge specific capacity (181.7 mAh/g) with excellent capacity retention (91.9 %) after 200 cycles (1 C, 2.7–4.3 V). Even at a high cutoff voltage (4.5 V) and high temperature (50 °C), the capacity retention remained high at 83.7 % and 85.2 %, respectively, after 200 cycles. Overall, in-situ Zr doping effectively resolves structural deterioration in the cores of the particles and improves the electrochemical properties of FCG Ni-rich layered cathodes.

Enhanced Lithium-Ion Transport in Lithium Metal Batteries Using ZSM-5 Nanosheets Hybridized Solid Polymer Electrolytes.

Solid polymer electrolytes (SPEs) are the key components of lithium metal batteries to overcome the obstacle of insecurity in conventional liquid electrolytes; however, the trade-off between their ionic conductivity and mechanical properties remains a significant challenge. In this work, two-dimensional ZSM-5 nanosheets as fillers are incorporated into a poly(ethylene oxide) (PEO) matrix and lithium salts to obtain composite polymer electrolytes (CPEs). The improved physicochemical and electrochemical properties of the CPE membranes are characterized in full detail. Stripping/plating measurements in symmetric Li/Li cells and cyclic charge/discharge tests are performed to investigate the cyclability and stability of the CPEs. All-solid-state LiFePO4/Li batteries deliver excellent cycling performance with an initial discharge capacity of 152.3 mAh g-1 and 91.4% capacity retention after 200 cycles at 0.2 C, with a discharge specific capacity of 118.8 mAh g-1 remaining after 350 cycles at 0.5 C. Therefore, CPEs containing ZSM-5 nanosheets are a promising option for all-solid-state lithium-ion batteries.

Redox-active polypyrrole/bacterial cellulose bilayer separator for lithium-ion batteries

Separator is one of the important elements of lithium-ion batteries, which affects both the capacity and safety performance of the batteries. In this paper, polypyrrole (PPy) was grown on bacterial cellulose (BC) nanofibers using in situ polymerization. A bilayered composite separator with PPy-coated BC conductive upper layer and BC insulating lower layer was prepared by paper-making method. The redox-active PPy could contribute to a specific discharge capacity of 119 mAh g−1 at 2C current density for the battery with the bilayered separator, which is significantly superior to the device with the polyolefin separator (73 mAh g−1). Moreover, the redox layer provided a low overpotential in the Li//Li symmetric cell cycle, which played an important role for the cycle stability of the lithium-ion batteries.

In Situ Hybrid Crosslinking Polymerization of Nanoparticles for Composite Polymer Electrolytes to Achieve Highly‐Stable Solid Lithium–Metal Batteries

AbstractThe composite solid electrolyte, which combines the advantages of inorganic conductors and organic polymer electrolytes, has become a crucial strategy for the construction of solid‐state batteries. However, the physical deposition and agglomeration of traditional composite fillers seriously affect their structural uniformity and ion transport performance, and the construction of uniform and stable composite electrolytes is still an insurmountable challenge. Herein, a strategy of in situ hybrid crosslinking polymerization of TiO2 nanoparticles is proposed for highly stable polymer composite electrolytes (NHCPE) with an ultrahigh ionic conductivity of 1.74 × 10−3 S cm−1 at 25 °C, and a high lithium‐ion transference number of 0.725. These properties enable the composed lithium symmetric battery to be stably deposited/plating off at 0.5 mA cm−2 for more than 1000 h. Moreover, the assembled LFP|PDOL@nanoTiO2|Li battery exhibits a superior specific discharge capacity of 142.6 mAh g−1 at 1 C and 25 °C, and an ultrahigh capacity retention rate of 90% after 1000 cycles. The proposed PDOL@nanoTiO2 NHCPE greatly inhibits the defects of easy agglomeration of composite electrolytes, solves the problems of easy decomposition, low thermal stability, and poor safety of polyether electrolytes, and opens up a new way for the design and industrial application of high‐stability composite polymer electrolytes.

Electrochemical methods for the removal of impurities from thegraphite anode in spent ternary lithium-ion batteries

The use of lithium-ion batteries (LIBs) is becoming increasingly widespread, and a large number are reaching their end of life. The recycling and re-use of spent LIBs has attracted great attention. Because of the unchanged layer structure of the graphite anode in these batteries, their recycling does not require high-temperature graphitization, and only focuses on the removal of internal impurities. We used electrochemical treatment for the deep removal of internal metal impurities after the heat treatment, ultrasonic separation, and acid leaching of spent graphite. By comparing and analyzing the graphite in different recovery stages, it was found that the presence of organic impurities seriously affects the electrochemical performance. The presence of trace inorganic impurities such as Cu and Fe has little effect on the initial discharge specific capacity, but reduces the cycling stability of graphite. The content of the main metal impurities in the final recycled graphite was less than 20 mg/kg. The discharge specific capacity reached358.7 mAh/g at 0.1 C, and the capacity remained at 95.85% after 150 cycles. Compared with the reported methods for recycling spent graphite, this method can efficiently remove impurities in the graphite, solve the current problems of high acid and alkali consumption, incomplete impurity removal and high energy consumption. The recycled graphite anode has a good electrochemical performance. Our work provides a new recycling and regeneration path for spent LIB graphite anodes.