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MnO has attracted much attention as the anode for Li-ion batteries (LIBs) owing to its high specific capacity. However, the low conductivity limited its large application. An effective solution to solve this problem is carbon coating. Biomass carbon materials have aroused much interest for being low-cost and rich in functional groups and hetero atoms. This work designs porous N-containing MnO composites based on the chemical-activated tremella using a self-templated method. The tremella, after activation, could offer more active sites for carbon to coordinate with the Mn ions. And the as-prepared composites could also inherit the special porous nanostructures of the tremella, which is beneficial for Li+ transfer. Moreover, the pyrrolic/pyridinic N from the tremella can further improve the conductivity and the electrolyte wettability of the composites. Finally, the composites show a high reversible specific capacity of 1000 mAh g−1 with 98% capacity retention after 200 cycles at 100 mA g−1. They also displayed excellent long-cycle performance with 99% capacity retention (relative to the capacity second cycle) after long 1000 cycles under high current density, which is higher than in most reported transition metal oxide anodes. Above all, this study put forward an efficient and convenient strategy based on the low-cost biomass to construct N-containing porous composite anodes with a fast Li+ diffusion rate, high electronic conductivity, and outstanding structure stability. [ABSTRACT FROM AUTHOR]

Due to its wide source and low cost, biomass-based hard carbon is considered a valuable anode for lithium-ion batteries (LIBs). Lignins, as the second most abundant source in nature, are being intensively studied as candidate anode materials for next generation LIBs. However, direct carbonization of pure lignin usually leads to low specific surface area and porosity. In this paper, we design a porous carbon material from natural lignin assisted by sacrificing a metal–organic framework (MOF) as the template. The MOF nanoparticles can disperse the lignin particles uniformly and form abundant mesopores in the composites to offer fast transfer channels for Li+. The as-prepared carbon anode shows a high specific capacity of 420 mAh g−1 with the capacity retention of 99% after 300 cycles at 0.2 A g−1. Additionally, it keeps the capacity retention of 85% after long cycle of 1000 cycles, indicating the good application value of the designed anode in LIBs. The work provides a renewable and low-cost candidate anode and a feasible design strategy of the anode materials for LIBs. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Sb 2 Se 3 @PPy cathode are designed for aluminum batteries. • The Sb 2 Se 3 @PPy cathode exhibits superior electrochemical performance. • The in-depth analysis on the electrochemical reaction mechanism. Aluminum batteries (ABs) are a promising alternative to lithium-ion batteries (LIBs) in the future. The development of aluminum batteries (ABs) is closely related to their cathode material. In this paper, we successfully designed and prepared a nanorod structure Sb 2 Se 3 @PPy as cathode material for ABs. It exhibits a high reversible capacity of 302 mAh/g at 0.2 A/g, and the capacity is maintained at about 210 mAh/g after 50 cycles. In addition, the electrochemical reaction mechanism and kinetic process of Sb 2 Se 3 @PPy were studied. The results showed that the PPy coating layer reduced the volume change of Sb 2 Se 3 , prevented irreversible deformation, enhanced the structural stability and electronic conductivity. [ABSTRACT FROM AUTHOR]

Two-dimensional tungsten disulfide (WS2) is a promising anode material for lithium-ion batteries. The further development of WS2 is restricted by the defects of electrical conductivity and structural stability. Here, a bimetallic sulfide/carbon composite WS2-X/CoS@C was prepared by a facile one-step MOFs-engaged method. The WS2/CoS heterojunctions and sulfur vacancies were introduced into the material, which improved the electronic/ionic diffusion kinetics of the composite. A large number of honeycomb carbon nanotubes were formed on the surface of the composite, which could effectively increase the specific surface area and enhance the conductivity of the composite. The WS2-X/CoS@C electrode exhibited excellent electrochemical performance used as an anode for lithium-ion battery. The initial discharge capacity of the WS2-X/CoS@C delivered 936 mAh/g at 100 mA/g and retained high discharge capacity of 600 mAh/g at 200 mA/g after the 100 cycles. [ABSTRACT FROM AUTHOR]

[Display omitted] • A mesoporous membrane with coordination effect of cellulose and MOF was designed. • The cellulose rich in –OH enabled the membrane with good electrolyte wetting. • MOF offer unsaturated metal sites to catch the anion and promote Li+ transfer. • The membrane has high Li+ conductivity of 2.189 mS cm−1. • The membrane shows excellent thermal stability up to 210 ℃. At present, the commercial polyolefin membranes for lithium-ion battery (LIBs) usually have poor thermal stability, poor wettability and high cost. Herein, we developed a sustainable mesoporous membrane with good anionic grabbing effect based on the biomass cellulose co-engineered with the metal–organic frameworks (MOFs). The abundant oxygen-containing functional groups in cellulose can enhance the affinity of the membrane with the electrolyte. And the coordination of the metal ions in MOFs with the functional groups in cellulose not only prevents the aggregation of the cellulose to form uniform porous structure, but also enhances the mechanical strength of the membrane. More importantly, the MOFs has appropriate mesopore size and strong cationic site, which can crab the PF 6 - anions in the electrolyte, thus promoting the fast transfer of Li+, thereby inhibiting the growth of lithium dendrite. In summary, this work put forward a simple and efficient strategy for designing the membrane with fast Li+ transfer, high safety and thermal stability and for LIBs. [ABSTRACT FROM AUTHOR]

LiNi 0.5 Co 0.2 Mn 0.3 O 2 cathode material synthesized by a sol-gel method was surface-modified by double-layer coating. The results of X-ray diffraction (XRD) confirm that the intrinsic structure was no change after surface modification. A double-layer structure consisting of an inner V 2 O 5 (VO) layer and an outer conductive graphene oxide (GO) layer was coated on the surface of active material, as confirmed by transmission electron microscopy (TEM). The results of field emission scanning electron microscope (FE-SEM) equipped with an energy dispersive spectroscope (EDS) show that both graphene oxide and V 2 O 5 uniformly covered LiNi 0.5 Co 0.2 Mn 0.3 O 2 cathode material. The double-layer-coated LiNi 0.5 Co 0.2 Mn 0.3 O 2 cathode material shows improved electrochemical performance with a capacity retention of 74.2% after 50 cycles in a range of 2.5–4.5 V at 55 °C, compared with only 67.8% capacity retention for the pristine material. In addition, the double-layer-coated LiNi 0.5 Co 0.2 Mn 0.3 O 2 releases 116.6 mAh g −1 under a high current rate, while the pristine material only remains at 105.7 mAh g −1 . The results can be ascribed to the double coating layer not only avoids the side reaction between electrolyte and active material but also promotes Li + and electronic conductivity. Differential capacity (dQ/dV) and electrochemical impedance spectroscopy (EIS) measurements reveal that the double coating layer effectively suppresses the increase of the electrode polarization during cycling. [ABSTRACT FROM AUTHOR]

Abstract: Li[Co1−z Al z ]O2 (0≤ z ≤0.5) samples were prepared by co-precipitation and solid-state methods. The lattice constants varied smoothly with z for the co-precipitated samples but deviated for the solid-state samples above z =0.2. The solid-state method may not produce materials with a uniform cation distribution when the aluminum content is large or when the duration of heating is too brief. Non-stoichiometric Li x [Co0.9Al0.1]O2 samples were synthesized by the co-precipitation method at various nominal compositions x =Li/(Co+Al)=0.95, 1.0, 1.1, 1.2, 1.3. XRD patterns of the Li x [Co0.9Al0.1]O2 samples suggest the solid solution limit is between Li/(Co+Al)=1.1 and 1.2. Electrochemical studies of the Li[Co1−z Al z ]O2 samples were used to measure the rate of capacity reduction with Al content, found to be about −250±30 (mAh/g)/(z =1). Literature work on Li[Ni1/3Mn1/3Co1/3−z Al z ]O2, Li[Ni1−z Al z ]O2 and Li[Mn2−y Al y ]O4 demonstrates the same rate of capacity reduction with Al/(Al+M) ratio. These studies serve as baseline characterization of samples to be used to determine the impact of Al content on the thermal stability of delithiated Li[Co1−z Al z ]O2 in electrolyte. [Copyright &y& Elsevier]

The commercial graphene for Li ion batteries (LIBs) has high cost and low capacity. Therefore, it is necessary to develop a novel carbon anode. The cellulose nanowires (CNWs), which has advantages of low cost, high carbon content, is thought as a good carbon precursor. However, direct carbonization of CNWs leads to low surface area and less mesopores due to its easy aggregation. Herein, the metal-organic frameworks (MOFs) have been explored as templates to prepare porous carbon due to their 3D open pore structures. The porous carbon was developed with the coordination effect of CNWs and MOFs. The precursor of MOFs coordinates with the −OH and − COOH groups in the CNWs to provide stable structure. And the MOFs was grown in situ on CNWs to reduce aggregation and provide higher porosity. The results show that the porous carbon has high specific capacity and fast Li+/electronic conductivity. As anode for LIBs, it displays 698 mAh g−1 and the capacity retention is 85 % after 200 cycles. When using in the full-battery system, it exhibits energy density of 480 Wh kg−1, suggesting good application value. This work provides a low-cost method to synthesize porous carbon with fast Li+/electronic conductivity for high-performance LIBs. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hierarchical porous Na 3 V 2 (PO 4) 3 @C microsphere is obtained by a solvothermal method. • Na 3 V 2 (PO 4) 3 @C cathode exhibits outstanding electrochemical properties. • A Li/Na hybrid ion full cell is designed with Na 3 V 2 (PO 4) 3 @C and lithiated graphite. • The full cell releases a capacity retention rate of 89.0% after 12,000 cycles at 5C. • Hybrid Li/Na ions storage mechanism in Na 3 V 2 (PO 4) 3 @C is elaborately clarified. Developing Li/Na hybrid ion batteries that combine both the superiorities of lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) is an unremitting pursuit for large-scale energy storage. Herein, hierarchical porous Na 3 V 2 (PO 4) 3 @C (NVP@C) microspheres as Li/Na hybrid ion batteries (HIBs) cathode are presented, which is synthesized through a solvothermal method. The hierarchical porous microspheres composed by the nanosheets endow short Li/Na-ions diffusion paths and structural integrity, improve electron conductivity, and increase reaction active sites. As a result, the hierarchical porous NVP@C cathode exhibits a high discharge capacity (119.1 mAh g−1 at 0.2C), remarkable rate performance (74.3 mAh g−1 at 50C) and cycling stability (a capacity fade of 0.64% at 1C over 500 cycles). More importantly, the assembled NVP//G full cell using the NVP@C cathode and lithiated graphite anode releases a highest reversible capacity of 118.1 mAh g−1 based on the cathode active material mass at 5C and a capacity retention rate of 89.0% after 12,000 cycles. In addition, the Li/Na ions synergistic storage mechanism in the NVP@C cathode material has been elaborately clarified via in situ X-ray diffraction (XRD) and ex situ X-ray photoelectron spectroscopic (XPS) tests. This work demonstrate that our Li/Na HIBs are a prospective device for large-scale energy storage. [ABSTRACT FROM AUTHOR]