Superior Electrochemical Performance For Lithium-ion Batteries Research Articles

Exploring inexpensive electrodes for safer and evolved dual-ion batteries using modified electrolytes for enhanced energy density

The current era of energy-storage systems has been inspired by lithium dual-ion batteries (Li-DIBs) owing to their advantages, including low cost, safer features, faster charging ability, and high energy density. Herein, we employed a rust-derived rhombohedral hematite nanosphere (Fe2O3-NS) anode for lithium-ion batteries (LIBs) synthesized using simple high-energy ball milling at different milling times (12, 24, and 36 h), followed by an annealing process. Specifically, the Fe2O3-NS-24 h electrode exhibited a superior electrochemical performance for LIBs owing to its large surface area and mesoporous nature, which are responsible for fast kinetics with a 4.41 × 10-10 cm2 s−1 diffusion coefficient. Li-DIBs were successfully designed with Fe2O3-NS-24 h as the anode, LiPF6 (1.0 M) in 1:1 (V/V) ethylene carbonate: di-ethylene carbonate with 0.013 M LiNO3 additive as the electrolyte, and expanded graphite as the cathode [referred to as Fe2O3-EG Li-DIB@LN]. Its performance was compared with those of Li-DIBs without additives. This investigation proves that LiNO3 additives deliver numerous advantages, including inexpensive high-voltage batteries, enhanced energy density, and Coulombic efficiency (CE). This could be owing to the creation of a smooth, flat, and intact solid electrolyte interface film on the electrode interface, improved cyclability and capacity, and safer fast-charging for Li-DIBs. Fe2O3-EG Li-DIB@LN exhibited a specific capacity of 69.1 mAh g−1 after the 50th cycle at a 0.1 A g−1 rate and had a modest specific energy density of ∼ 238.3 Wh kg−1 with stable CE. These findings highlight a new route for employing LiNO3 additives to intensify the energy density, CE, and overall performance of Li-DIBs.

In-situ formed porous heteroatomic ladder polymer-based fibrous composite anode for high-rate and ultrastable lithium-ion batteries

Heteroatomic ladder polymers (HLPs) with high theoretical capacity are considered as the most promising electrode materials for next-generation green sustainable lithium-ion batteries (LIBs) due to their abundant resources, low cost, diverse structures and good safety features. However, the issues of low specific capacity and unsatisfactory reversibility, caused by underutilization and sluggish reaction kinetics, have thus far hindered the practical application of these materials. Herein, a porous heteroatomic ladder polymer-based fibrous composite anode (HLP/RGO/C) with interconnected conductive networks is designed and obtained by a simple electrospinning technique and in-situ heat treatment for LIB applications. Benefit from in-situ transformation and interconnected conductive porous networks, the obtained HLP/RGO/C anode achieves uniform distribution of HLP and rapid ionic/electronic transport, thereby realizing efficient utilization and rapid reaction kinetics of HLP in LIBs. Consequently, the HLP/RGO/C anode achieves a highly reversible specific capacity of 748 mA h g−1, ultra-long cyclic stability and exceptional rate performance for LIBs. Furthermore, the HLP/RGO/C anode also delivers superior electrochemical performance for LIBs over a broad temperature range, especially achieving ultrahigh reversible capacities of 186 mA h g−1 even at −30 °C. This research provides a straightforward method to construct green and sustainable polymer-based anode for LIBs.

Ag nanoparticles grafted vanadium carbide MXene as a superior anode material for lithium-ion battery: High capacity and long-term cycle capability

V 2 CT x MXene shows excellent potential in lithium-ion batteries (LIBs) due to its unique two-dimensional structure and rich surface chemistry. However, the low Li + -storage capacity contributed by the innate low conductivity seriously hinders its commercial application. Herein, Ag nanoparticles are grafted on the V 2 CT x MXene by a one-step reduced silver nitrate (AgNO 3 ). The obtained Ag nanoparticles are directly reduced from AgNO 3 by the -OH terminations of V 2 CT x MXene, which promote the conductivity of V 2 CT x /Ag. Besides, the Ag nanoparticles in the layered body structure have excellent structural strength, which boost the whole durability of the LIB by inhibiting the aggregation of V 2 CT x MXene. Further, the dependence of the battery performances on the Ag contents is investigated. We find that the most favorable Ag content is 4.0 at% which can simultaneously favor the transferability of electron and ion and the electrochemical kinetics to the most considerable extent. The V 2 CT x /Ag-40 achieves a specific capacity of 631 mAh g −1 at 0.05 A g −1 after 50 cycles, and even maintains a specific capacity of 298 mAh g −1 at 5 A g −1 after long-term 2000 cycles. The adopted in situ reduction strategy and the excellent electrochemical property of V 2 CT x /Ag nanostructure may be relevant for future anode material in LIBs. We focused on the in situ reaction mechanism and the treated V 2 CT x has a greatly improved specific capacity. • V 2 CT x /Ag MXene was synthesized by one step solution in situ reaction and the reaction mechanism was analyzed. • V 2 CT x /Ag MXene exhibited superior electrochemical performance for LIBs. • The effect of different content of surface AgNPs on V 2 CT x MXene was analyzed.

Design of pseudocapacitance and amorphization Co-enhanced Mn3O4/graphene sheets nanocomposites for high-performance lithium storage

Mn3O4-based materials have been broadly investigated as anode materials for lithium- ion batteries (LIBs) due to their high energy densities, affordable cost, environmental benignity, etc. However, the wide voltage hysteresis due to inferior electronic conductivity and serious volume expansion during lithiation/delithiation seriously restricted their practical applications. In this work, Mn3O4/graphene sheet (MGS) nanocomposites were prepared by a solution reaction assisted calcination method, which led to superior electrochemical performance for LIBs and presented both high reversible capacity and excellent cyclic stability (1199.5 mAh g−1 after 600 cycles and 995.3 mAh g−1 after 1000 cycles at a current density of 500 mA g−1). The superior cyclic stability could be attributed to the amorphization effect of Mn3O4 and strong coupling interaction between Mn3O4 and graphene sheets. On one hand, the highly oxidized Mn3O4 and increasing Li+ active sites during extended cycles are beneficial to achieve high specific capacity. Meanwhile, the strong coupling effect, fast pseudocapacitive reaction and amorphous phase effect help provide numerous voids, which effectively alleviate volume expansion and enable excellent cyclic stability, enriching their great opportunities for LIBs anode materials with narrow voltage hysteresis and long cycle life.

Novel in-situ redox synthesis of Fe3O4/rGO composites with superior electrochemical performance for lithium-ion batteries

Coupling transition metal oxides with nanocarbonaceous materials is an effective approach to construct high-efficiency anode materials for lithium-ion batteries (LIBs). In the present study, we demonstrate a novel in-situ redox strategy for facile and cost-effective synthesis of Fe3O4/reduced graphene oxide (Fe3O4/rGO) composites as LIBs anodes. Fe3O4/rGO composites are facilely obtained through redox reaction between highly-oxidized graphene oxide and ferrous salt under basic atmosphere, followed by stabilization treatment ranging from 5 min to 5 h. Well crystallized Fe3O4 nanoparticles with diameters of 10–30 nm are tightly and homogeneously anchored on the flexible graphene substrate. Owing to the distinctive composite nanostructure, including strong integration, homogeneous distribution and surface modification effect, the as-prepared Fe3O4/rGO composites exhibit superior electrochemical lithium-storage performance, especially at high current densities. The Fe3O4/rGO-2h composite delivers a remarkable reversible capacity of 1024 mA h g−1 at the current density of 1000 mA g−1, and retains 584 mA h g−1 at 5000 mA g−1 even after 450 cycles. It is believed that the study will provide a feasible strategy to facilely produce transition metal oxide/carbon composite electrodes with superior electrochemical performance for LIBs.

Intercalating petroleum asphalt into electrospun ZnO/Carbon nanofibers as enhanced free-standing anode for lithium-ion batteries

In this study, we demonstrate novel 3D interconnected nanofiber films by intercalating petroleum asphalt into electrospun ZnO/carbon nanofibers (ZnO/CNFs-PA) as enhanced free-standing anode for lithium-ion batteries (LIBs). ZnO/CNFs composite is synthesized via one-step electrospinning of polyacrylonitrile and zinc acetate dehydrate. Through solvent impregnation and subsequent two-step thermal treatments, appropriate amount of petroleum asphalt (PA) is intercalated into ZnO/CNFs to generate a conductive carbon film between and around the nanofibers. Benefitting from the 3D conductive network established by the carbon nanofibers and PA-carbon layer, the as-prepared ZnO/CNFs-PA-1.0 film is evaluated as a free-standing LIBs anode and exhibits a promoted reversible capacity of 702 mA h g−1 at current density of 200 mA g−1, associating with excellent cycling stability and rate performance. Such novel nanostructure can effectively accommodate the volume expansion of ZnO, facilitate charge transfer and reinforce the electrode. The present strategy is believed to provide a feasible method to produce transition metal oxide/carbon nanofibers electrodes with superior electrochemical performance for LIBs.