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[Display omitted] • The supercritical CO 2 fluid with excellent permeability could construct uniform and injected oxygen defect engineering. • The modified cathode shows an initial coulombic efficiency of 96.6%, excellent capacity retention of 91.96% at 1C after 200 cycles. • The injected oxygen defect extends protection into bulk region, suppresses unfavorable lattice volume change and preserves structural integrity. • Oxygen defects reduce orphaned O energy level and narrow the energy gap between TM nd orbitals and O 2p orbitals to improve anionic reversibility. Lithium-rich layered cathode materials are considered to be research focus of cathode candidates for next-generation lithium-ion batteries due to their high specific capacity and low cost. However, lattice deoxidation associated with elemental migration and internal local shrinkage usually results in deteriorated cyclic performance and notorious voltage attenuation, severely limiting its application. In this paper, we have successfully injected uniform oxygen defects into surface region of Li 1.2 Ni 0.13 Co 0.13 Mn 0.54 O 2 primary particles under the high-pressure and weak carbonate environment. Various experimental investigations indicate that the injected robust oxygen defects can not only mitigate detrimental interfacial reactions but also suppress unfavorable lattice variation and particle breakage. More importantly, theoretical calculations unravel the critical roles of oxygen defects in regulating energy band structure for strengthened anionic reversibility. Owing to stabilization effects of unique oxygen defect engineering, the modified Li 1.2 Ni 0.13 Co 0.13 Mn 0.54 O 2 cathode has harvested dramatically enhanced electrochemical performance including a high initial coulombic efficiency of 96.6%, an outstanding capacity retention of 91.96% (1C, 200 cycles) and suppressed voltage decay of only 1.62 mV per cycle. Therefore, this facile and effective defect engineering strategy could establish new guidance for promoting practical application of Li-rich Mn-based cathode material. [ABSTRACT FROM AUTHOR]

The adsorption behaviors and adsorption mechanism of HTO-s were systematically investigated by experiments and DFT calculations, which indicates the adsorption performance was influenced by adsorbents surface with different facets and dehydration processes. [Display omitted] • The HTO-OS with dominant (111) facet and HTO-NS with dominant (01-1) facet were synthesized. • The adsorption tests show that HTO-NS possesses faster adsorption rates and more stable recyclability than HTO-OS. • The dehydration processes of Li(H 2 O) 4 + on HTO (01-1) and (111) are partially dehydrated to form Li(H 2 O)+ and Li(H 2 O) 2 + via DFT calculations. • The study helps to better understand the effect of dehydration behavior on the Li+ adsorption in aqueous lithium resources. In this study, octahedrons assembled nanospheres Li 4 Ti 5 O 12 (LTO-OS) with dominant (111) facet and nanosheets assembled microspheres Li 4 Ti 5 O 12 (LTO-NS) with dominant (01-1) facet precursors were synthesized. Then, these corresponding H 4 Ti 5 O 12 adsorbents (HTO-OS and HTO-NS) were obtained via acid treatment and used to recover lithium from aqueous solutions. The systematic adsorption tests show that HTO-NS possesses higher adsorption uptake (35.5 mg/g) and faster adsorption rate (equilibrium time: <2 h) than HTO-OS (31.2 mg/g), owing to the role of different dehydration processes and exposed facets. With the help of DFT calculation analyses, the dehydration of Li(H 2 O) 4 + on HTO (01-1) and (111) were partially dehydrated Li(H 2 O)+ and Li(H 2 O) 2 + in the adsorption process, owing to crystal channel and surface atomic arrangement. In addition, the analysis of the adsorption mechanism indicates that the Li+ exist in the form of hydrated lithium ions in the initial adsorption solution, and the dehydration processes occur during Li(H 2 O) 4 + move to the surface of the adsorbent, then an ion exchange reaction has happened between the dehydrated Li+ and H+. These results reveal the adsorbents with different facets exposed indeed influence the surface dehydration processes and Li+ adsorption behaviors, which are favorable to better understand the interfacial interactions between adsorbents and adsorbates. [ABSTRACT FROM AUTHOR]

[Display omitted] • The bifunctional Li 3 Bi-LiBr protective layer is prepared to stabilize Li 7 P 3 S 11 /Li interface via a simple in-situ reaction. • DFT calculations reveal low surface barrier of Li 3 Bi and high interface energy of LiBr. • Li 3 Bi-LiBr modified Li symmetric cells exhibit increased CCD to 0.838 mA/cm2 and cycle stably at 0.5 mA/cm2 at room temperature. • The modification strategy provides possibility for the application of sulfide electrolyte based ASSLMB. All-solid-state lithium metal batteries (ASSLMBs) are well known as the most promising high-energy-density storage systems. However, the unstable interface between sulfide solid electrolyte and lithium (Li) metal anode limits the application of lithium metal in sulfide-based ASSLMBs. Herein, the bifunctional Li 3 Bi-LiBr protective layer is constructed via a simple in-situ reaction between BiBr 3 and lithium metal to solve the instability issue of the Li 7 P 3 S 11 /lithium interface. The merits of the Li 3 Bi-LiBr protective layer reflect in the low surface barriers of Li 3 Bi and the high interface energy of LiBr by density functional theory (DFT) calculations. The combination of both can effectively promote lithium diffusion and avoid lithium aggregation, thus inhibiting the growth of lithium dendrite. Results show that the Li-LBB/Li 7 P 3 S 11 /LBB-Li symmetric battery exhibits dramatically increased critical current density (0.838 mA/cm2) and long cycling lifespan (over 2000 h at 0.1 mA/cm2 and 0.5 mAh/cm2) at room temperature. In addition, a distinct capacity retention enhancement about 19.03% is embodied in the LiNbO 3 @LiCoO 2 /Li 7 P 3 S 11 /LBB-Li full cell. [ABSTRACT FROM AUTHOR]

The adsorption behavior and mechanism of H 4 Ti 5 O 12 (1 1 0) and H 4 Ti 5 O 12 (1 1 1) were systematically investigated by experiments and theory calculations, which indicates H 4 Ti 5 O 12 (1 1 1) has more potential on Li+ recovery. [Display omitted] • The H 4 Ti 5 O 12 with (1 1 0) and (1 1 1) facets exposed were synthesized. • The adsorption uptake of H 4 Ti 5 O 12 (1 1 1) is higher than that by H 4 Ti 5 O 12 (1 1 0). • The adsorption of [Li(H 2 O) 4 ]+ on H 4 Ti 5 O 12 (1 1 1) is more stable than (1 1 0). • Li+ is easier diffused from (1 1 1) facet into Li 4 Ti 5 O 12 crystal than (1 1 0) facet. The improved adsorption capacities by increasing specific surface area methods are merely reached about 50% of H 4 Ti 5 O 12 's theoretical adsorption capacity, and the adsorption behavior and mechanism of lithium on special facets of H 4 Ti 5 O 12 remain unclear. In this study, a flower-shaped Li 4 Ti 5 O 12 and an octahedral Li 4 Ti 5 O 12 were prepared with the specific surface areas of 176.23 and 83.02 m2/g, and the corresponding adsorption behaviors of the obtained adsorbents exposed with (1 1 0) and (1 1 1) facets were investigated by using experimental and computational methods. The maximum Li+ uptake values on H 4 Ti 5 O 12 (1 1 0) and H 4 Ti 5 O 12 (1 1 1) are 26.85 mg/g and 33.56 mg/g at 45 °C in 24 mM LiCl solutions, respectively. The fifth reuse ability of H 4 Ti 5 O 12 (1 1 1) still remains 88.9% of the original's, which is higher than H 4 Ti 5 O 12 (1 1 0) (76.3%). Although with lower specific surface area, the octahedral H 4 Ti 5 O 12 have higher ions selectivity, greater adsorption capacity, and better reuse ability than flower-shaped H 4 Ti 5 O 12 , which may due to the special (1 1 1) facet exposed. Firstly, H 4 Ti 5 O 12 (1 1 1) owned small hole sizes can inhibit other ions diffusing into H 4 Ti 5 O 12 and improve the ion selectivity. Secondly, the immigration paths by the First-principles calculations revealed that the Li+ migrate onto the Li 4 Ti 5 O 12 (1 1 1) is easier to than Li 4 Ti 5 O 12 (1 1 0) through 8a-16c-8a-16c sites. At last, [Li(H 2 O) 4 ]+ can form the stable complexes and its adsorption energies on (1 1 1) are higher than on (1 1 0) facets, which may lead to larger adsorption capacity and better reuse ability. This work will help to understand the [Li(H 2 O) 4 ]+ adsorption behavior and mechanism on different crystal facets by experiments and computations. [ABSTRACT FROM AUTHOR]

[Display omitted] • H 3 LiTi 5 O 12 (HTO) nanoparticles with high Li+ selectivity were synthesized. • HTO-AC based cathode was used to electro-sorb Li+ from both simulated and raw brine. • Electricity can enhance the Li+ adsorption kinetics and capacity by HTO. • Li+ adsorption energy on HTO surface was analyzed by DFT calculation. The rapid consumption of lithium ion (Li+) battery for electronic devices has significantly increased the demand for lithium resource in recent years. The salt-lake brine is considered as the ideal source for Li+ extraction, but the co-existing cations, such as Na+ and K+ limit its recovery efficiency when the adsorption method is applied. In this study, the H 3 LiTi 5 O 12 nanoparticles (HTO) with a spinel structure were synthesized as Li+-selective adsorbent. The static adsorption experiments showed that the Li+ absorption capacity of HTO was significantly affected by the pH of bulk solution, and exhibited a high separation factor of Li+/Na+ and Li+/K+ at 37 and 16, respectively. When HTO was mixed with activated carbon (AC) and coated on the cathode plate, the Li+ adsorption kinetics (rate constant) was significantly enhanced from 0.18 to 0.25, due to the accelerated rate of the film diffusion driven by the electric field. Density functional theory (DFT) calculation result showed that applying electricity can strengthen the hydrogen bond between Li and O atom on the HTO (1 1 1) facet. When the AC mixing ratio was increased from 10% to 50%, the Li+ desorption efficiency increased from 47% to 90%, but at the expense of sacrificing the adsorption capacity, which decreased from 18.1 mg/g to 9.8 mg/g. In terms of the overall recovery efficiency of Li from brine, the weight ratio of HTO:AC at 9:1 was suggested for the electro-sorption method. Finally, the Li+ recovery from actual brine was successfully demonstrated, with 7.1 mg/g of adsorption capacity and well stability. [ABSTRACT FROM AUTHOR]

In this work, the effectiveness of dual-additives electrolyte consisting of iodine and caffeic acid (noted as CA@I) in improving electrochemical performance has been demonstrated both experimentally and theoretically. The full cell with a high LiFePO 4 loading (17.4 mg cm−2, 3.0 mAh cm−2) has successfully demonstrated a stable lifetime of more than 370 cycles with a capacity retention of 95.0%. [Display omitted] • A novel iodine and caffeic acid dual-additive electrolyte was proposed for Li metal batteries. • I 3 −/I− redox couple can rejuvenate inactive lithium and be revived itself at the cathode side. • The anionic polymerised caffeic acid modulates composition and improve stability of SEI. • The modified Li|Li battery achieves an ultra-long cyclelife over 7000 h at 1 mA cm−2. Inactive ('dead') lithium and conventional fragile solid-electrolyte interphase (SEI) usually cause performance degradation and safety hazards in Li-metal batteries. Recovering inactive lithium and constructing stable SEI are urgently required to enhance the capacity and lifespan of lithium metal batteries. Herein, we have designed a novel dual-additives electrolyte containing an I 3 −/I− redox couple for reviving the inactive lithium, and caffeic acid (CA) that can be anion-polymerised to modulate the composition and improve stability of the SEI. It's found that the generated I 3 −/I− redox couple can turn the inactive Li 2 O into soluble Li+, and prompt the formation of SEI composed of inorganic LiI, Li 3 N and organic RCOOLi with high stability. Density functional theory (DFT) calculations indicate that the diffusion potential barrier of Li+ is significantly lower on the LiI-rich SEI interface, which can not only accelerate the transport of Li+ at the interface, but also effectively prevent I 3 − from attacking Li metal. Benefiting from this elaborate dual-additives electrolyte design, the symmetrical-cells present a superior electrochemical performance, i.e., high critical current density up to 10 mA cm−2, ultra-long lifespan over 7000 h at 1 mA cm−2, and over 2500 cycles under harsh conditions of high temperature (50 °C) and high current density (5 mA cm−2). In addition, as a proof of concept for practical applications of Li-metal batteries, Li|LiFePO 4 full cell delivers excellent cycle stability and rate performance with low hysteresis voltage at a high cathode loading of 17.4 mg cm−2. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • SnO 2 /Cu/graphene composite is synthesized by a one-pot selective reduction method. • N 2 H 4 ·H 2 O deduces the selective reduction of Cu2+ to Cu and only hydrolysis of Sn2+. • Cu NPs promote charge transfer, compress volume stress and obstruct Sn aggregation. • Conversion reaction of Sn/Li 2 O to SnO 2 is highly reversible over 200 cycles. • SnO 2 /Cu/graphene composite demonstrates extraordinary long-term cycle stability. Abstract Low electronic conductivity and the tin coarsening caused irreversible capacity loss are the primary cause of poor cycle performances in SnO 2 materials. In this work, a ternary SnO 2 /Cu/graphene composite is synthesized by a one-pot selective reduction method to improve the cycle life of SnO 2 -based composite anode. During the liquid-phase synthesis process, the Cu2+ and Sn2+ cations are adsorbed uniformly on the surface of GO sheets under electrostatic attraction, which are then selective reduced by N 2 H 4 ·H 2 O because of its moderate reduction falling in between these two components (Eϴ (Cu 2+ /Cu) 0.34 V > Eϴ (Sn 2+ /Sn) −0.14 V). The electrochemical active SnO 2 and inactive Cu nanoparticles anchor tightly on the flexible conductive graphene sheets and locate in close proximity to each other. Cu nanoparticles can promote the charge transfer kinetics of insulating SnO 2 at the interfaces, compress the volume stress as lithium ions insertion/deinsertion, and obstruct the aggregation of metallic Sn and Li x Sn alloy, thus continuously promoting the reversibility of conversion reaction from Sn/Li 2 O to SnO 2. The as-prepared composite displays an excellent long-term cycling stability, delivering a reversible capacity of 890.6 mAh g−1 at 100 mAg−1 even after 200 cycles without any capacity decay. The excellent cyclic stability and facile liquid-phase synthesis method demonstrate the promising candidate of the Cu nanoparticles in stabilizing the reversible capacity of SnO 2 /graphene composite and its candidate in scalable application. [ABSTRACT FROM AUTHOR]

Mercuric ion (Hg 2+ ) is a toxic metal ion in the environment, which will seriously damage the people's health. Therefore, the simple sensitive detection of Hg 2+ is of great significance. In this work, Ag-CoFe 2 O 4 /reduced graphene oxide (rGO) nanocomposites were synthesized via a one-pot microwave-assisted reaction, which can directly oxidize 3, 3′, 5, 5′-tetramethylbenzidine (TMB) to produce a light blue. Then we have developed a dual colorimetric and SERS detection of Hg 2+ based on the stimulus of intrinsic oxidase-like catalytic activity of Ag-CoFe 2 O 4 /rGO nanocomposites. It is demonstrated that the interaction between Hg 2+ and Ag nanoparticles can occur in a short time, which includes the formation of Ag-Hg alloy due to the reduction of Hg 2+ . In addition, the formation of such alloy can enhance the oxide-like activity, which makes the detection of Hg 2+ more sensitive. By using the SERS detection approach, the assay can detect Hg 2+ as low as 0.67 nM. This detection ability is much better than previous reports based on the enzyme-like catalytic reaction, which is also lower than the maximum value of Hg 2+ permitted in drinking water by the World Health Organization (WHO) (30 nM) and United States Environmental Protection Agency (EPA) (10 nM). In addition, this detection system also shows an excellent selectivity toward Hg 2+ due to the affinity of Hg to Ag-CoFe 2 O 4 /rGO nanocomposites. Therefore, this approach is potentially applicable for the sensitive determination of Hg 2+ in real environmental conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] • The rationality of Li deposition under chlorinated SEI was clarified by DFT. • A stable chlorinated hybrid SEI layer has been designed on the Li metal surface. • The enriched LiCl inhibits the growth of Li metal on SEI surface. • LFP|Li cells exhibit longer lifespan under ultrahigh loads (17.4 mg cm−2). Lithium (Li) metal is the ultimate anode material for use in next-generation batteries in the pursuit of higher energy densities. However, the traditional solid electrolyte interphase (SEI) owns the disadvantages of large interfacial impedance, low Li ions migration rate and easy fragility. Herein, this is the first report that reveals in detail the rationality of Li deposition beneath the chlorinated hybrid layer and fast ion transport kinetics at LiCl/Li interface through density functional theory (DFT) estimation. Based on this, an artificial SEI layer enriched with LiCl, LiZn alloy and in-situ ring-opening polymerization of poly(tetrahydrofuran) (PTMG) is constructed on lithium metal surface. The glow-discharge optical emission spectroscopy (GD-OES) results revealed that LiCl is mainly enriched on the surface of the artificial SEI, its excellent electron-blocking ability could inhibit the electron flow tunneling from the Li metal to SEI, which prevents the generation of Li0. As expected, the Li metal anode with an artificial chlorinated hybrid SEI layer exhibits excellent cycle performance over 2000 h with lower overpotential of 11 mV at 1 mA cm−2. Moreover, full-cell delivers higher capacity retention and coulombic efficiency after long cycles under high LiFePO 4 loading (at 17.4 mg cm−2, 3.0 mAh cm−2). [ABSTRACT FROM AUTHOR]

• Simultaneously achieved high η of ∼83% and large W rec of ∼7.13 J/cm3 for 0.28NBCT ceramic. • Excellent temperature and frequency stabilities are obtained. • High C D of 1073 A/cm2 and P D of 161 MW/cm3 are acquired. • High discharge energy density of 3.4 J/cm3and fast discharge time of 40 ns are obtained. Lead-free relaxor ferroelectric ceramic capacitors have attracted increasing attention for their excellent energy-storage performance. In this work, Na 0.5 Bi 0.5 TiO 3 was modified by linear dielectric Ca 0.85 Bi 0.1 TiO 3 to improve its energy storage performance. The samples of (1- x)Na 0.5 Bi 0.5 TiO 3 - x Ca 0.85 Bi 0.1 TiO 3 , namely Na 0.5-0.5 x Bi 0.5-0.4 x Ca 0.85 x TiO 3 (x NBCT, x = 0, 0.14, 0.21, 0.28, and 0.35) were prepared by solid-state reaction method. The structure, dielectric, energy storage capability, and pulsed charging/discharging behaviors of the ceramics were investigated in detail. Our results showed that CBT doping into the NBT-based ceramics is beneficial to energy storage. A large recoverable energy storage density of 7.13 J/cm3 and a high efficiency of 83% can be achieved simultaneously in the 0.28NBCT ceramic. The 0.28NBCT ceramic also exhibits good temperature and frequency stability with an ultrahigh power density of 161 MW/cm3, a transient discharge time of 40 ns, and high discharge energy density of 3.4 J/cm3. These findings indicate that the sample of 0.28NBCT has great prospects in pulsed-power applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • A uniform and small-sized (ca. 10 nm) core–shell Ag/o-GQDs nanohybrid are successfully prepared. • The Ag/o-GQDs show unique structure with parallel-interlaced staking of o-GQDs. • The Ag/o-GQDs exhibit excellent SERS sensitivity, biocompatibility and nanozymatic activity. • The intracellular H 2 O 2 can be accurately in situ SERS monitoring at the subcellular level. The small-sized plasmonic nanoparticles are easily internalized by cells and organelles, but usually possess poor surface-enhanced Raman scattering (SERS) activity, restricting their promising applications for intracellular SERS analysis. To break the current bottleneck of intracellular SERS application, herein, a uniform and small-sized (ca. 10 nm) core–shell Ag/oxidized graphene quantum dots (o-GQDs) nanohybrids have been prepared. The Ag/o-GQDs inherit unique features with parallel-interlaced stacking of o-GQDs as capping agent, possess the increasing and broadening plasmon adsorption and display a unique edge state charge transfer (CT) resonance in the long-wavelength region of visible light, enabling the enhanced electromagnetic (EM) and CT effect for superior SERS sensitivity at lower energy. Further, the Ag/o-GQDs demonstrate excellent biocompatibility and highly efficient nanozymatically catalytic activity, which are first put forward to integrate efficient SERS with Ag/o-GQDs nanozyme to catalyze peroxidase-like reaction for accurate sensing of the intracellular H 2 O 2 at the subcellular level. Moreover, the Ag/o-GQDs nanozyme-catalyzed reactive oxygen species (ROS) generation and the cancer cell multisubcellular-targeting capability provide a promising strategy for the synergistically catalytic therapy specifically toward tumors. This study illustrates a significant route to design an efficient small-sized noble metal/carbon nanozymatic SERS substrate, and demonstrates an exciting potential for ultrasensitive SERS bioanalysis at the subcellular level. [ABSTRACT FROM AUTHOR]

• The formation mechanism of Li 7 P 3 S 11 electrolyte in acetonitrile is studied. • The reaction in liquid is lone pair electrons on Li 2 S attacking bridge S on P 2 S 5. • The precipitate and soluble phases are Li 3 PS 4 ·ACN and Li 4 P 2 S 7 ·ACN, respectively. • Low conductivity of liquid-phase synthesized Li 7 P 3 S 11 is due to residual Li 4 P 2 S 6. • Soluble Li 4 P 2 S 7 can be obtained by reacting Li 3 PS 4 with Li 2 P 4 S 11 or Li 4 P 4 S 12 , etc. All-solid-state lithium batteries have been recognized as the next generation energy storage/conversion devices for many high-power and safe applications. Li 7 P 3 S 11 glass ceramics, as a promising solid electrolyte, has shown a high application possibility. Although the synthesis of Li 7 P 3 S 11 by wet-chemical method is more controllable and can be well matched with the existing battery preparation processes, the chemical reaction mechanism of such a liquid-phase reaction process is not fully understood, and also its ionic conductivity is lower than that obtained by solid-state methods. In this paper, we have clarified that the liquid-phase reaction is mainly the process of lone-pair electrons of Li 2 S to attack the bridged S on P 2 S 5 to obtain compounds with different element ratios, which is explored by recording different reaction times and adjusting different proportions of the phase transitions in acetonitrile (ACN) solvent. The only precipitate phase is found to be Li 3 PS 4 ·ACN, which can react with soluble phases with higher P content such as Li 2 P 4 S 11 , Li 4 P 4 S 12 and so on to obtain Li 4 P 2 S 7 for the formation of Li 3 PS 4 ·ACN and Li 4 P 2 S 7 ·ACN (molar ratio 1:1) in the liquid phase. Finally, Li 7 P 3 S 11 is formed by the equimolar reaction of above two compounds during the calcination. XPS and Raman results indicate that the low conductivity of liquid-phase synthesized Li 7 P 3 S 11 solid electrolyte may be induced by the residual Li 4 P 2 S 6 , which is caused by the inadequate contact and coverage of gel-like Li 4 P 2 S 7 with solid Li 3 PS 4 , resulting in the desulfurization reaction of Li 4 P 2 S 7 during the heat-treatment. [ABSTRACT FROM AUTHOR]