Li‐rich Mn‐based cathode materials (LRMs) are potential cathode materials for high energy density lithium‐ion batteries. However, low initial Coulombic efficiency (ICE) severely hinders the ...commercialization of LRM. Herein, a facile oleic acid‐assisted interface engineering is put forward to precisely control the ICE, enhance reversible capacity and rate performance of LRM effectively. As a result, the ICE of LRM can be precisely adjusted from 84.1% to 100.7%, and a very high specific capacity of 330 mAh g−1 at 0.1 C, as well as outstanding rate capability with a fascinating specific capacity of 250 mAh g−1 at 5 C, are harvested. Theoretical calculations reveal that the introduced cation/anion double defects can reduce the diffusion barrier of Li+ ions, and in situ surface reconstruction layer can induce a self‐built‐in electric field to stabilize the surface lattice oxygen. Moreover, this facile interface engineering is universal and can enhance the ICEs of other kinds of LRM effectively. This work provides a valuable new idea for improving the comprehensive electrochemical performance of LRM through multistrategy collaborative interface engineering technology.
Introduced cation/anion double defects can reduce the interface charge transfer resistance and enhance the Li+ ion diffusion coefficient. The induced in situ surface reconstruction layer can increase the electronic conductivity and stabilize the surface lattice oxygen. As a result, the initial Coulombic efficiency of Li‐rich Mn‐based cathode material is controlled precisely.
Li‐rich cathode materials have attracted increasing attention because of their high reversible discharge capacity (>250 mA h g−1), which originates from transition metal (TM) ion redox reactions and ...unconventional oxygen anion redox reactions. However, many issues need to be addressed before their practical applications, such as their low kinetic properties and inefficient voltage fading. The development of cutting‐edge technologies has led to cognitive advances in theory and offer potential solutions to these problems. Herein, a recent in‐depth understanding of the mechanisms and the frontier electrochemical research progress of Li‐rich cathodes are reviewed. In addition, recent advances associated with various strategies to promote the performance and the development of modification methods are discussed. In particular, excluding Li‐rich Mn‐based (LRM) cathodes, other branches of the Li‐rich cathode materials are also summarized. The consistent pursuit is to obtain energy storage devices with high capacity, reliable practicability, and absolute safety. The recent literature and ongoing efforts in this area are also described, which will create more opportunities and new ideas for the future development of Li‐rich cathode materials.
The practical applications of Li‐rich cathode materials, especially Li‐rich Mn‐based (LRM) cathodes, are hindered by their inherent shortcomings. In this case, the recent understanding of complex reaction mechanisms, the novel modification methods, and the corresponding development trends are comprehensively reviewed. Additionally, other branches and the future opportunities of the Li‐rich cathode materials are also summarized.
The synergetic mechanism of chemisorption and catalysis play an important role in developing high‐performance lithium–sulfur (Li–S) batteries. Herein, a 3D lather‐like porous carbon framework ...containing Fe‐based compounds (including Fe3C, Fe3O4, and Fe2O3), named FeCFeOC, is designed as the sulfur host and the interlayer on separator. Due to the strong chemisorption and catalytic ability of FeCFeOC composite, the soluble lithium polysulfides (LiPSs) are first adsorbed and anchored on the surface of the FeCFeOC composite and then are catalyzed to accelerate their conversion reaction. In addition, the FexOy in Fe‐based compounds can spontaneously react with LiPSs to form magnetic FeSx species with a larger size, further blocking the penetration of LiPSs cross the separator. As a result, the assembled Li–S cells show excellent long‐term stability (748 mAh g−1 over 500 cycles at 1.0 C, and ≈0.036% decay per cycle for 1000 cycles at 3.0 C), a superb rate capability with 659 mAh g−1 at 5.0 C, and lower electrochemical polarization. This work introduces a feasible strategy to anchor and accelerate the conversion of LiPSs by designing the multifunctional Fe‐based compounds with high chemisorption and catalytic activity, which advances the large‐scale application of high‐performance Li–S batteries.
The carbon framework containing Fe‐based compounds (FeCFeOC) composite can first anchor the soluble LiPSs on the surface of FeCFeOC by strong chemisorption, and then its catalytic effect can accelerate LiPSs redox kinetics. Moreover, the FexOy in FeCFeOC composite can spontaneously react with LiPSs to form magnetic FeSx species with a larger size, further blocking the penetration of sulfur active materials cross the separator.
Manipulating the local electronic structure is employed to address the capacity/voltage decay and poor rate capability of Li‐rich layered cathodes (LLOs) via the dual‐doping of Na+ and F− ions, as ...well as the regulation of Li+/Ni2+ intermixing and the content of “LiOLi” configuration. The designed cathode exhibits a high initial Coulombic efficiency of about 90%, large specific capacity of 296 mAh g−1 and energy density of 1047 Wh kg−1 at 0.2 C, and a superior rate capability of 222 mAh g−1 at 5 C with a good capacity retention of 85.7% even after 500 cycles. And the operating voltage is increased without compromising the high‐capacity advantage. Such improved electrochemical performances primarily result from the band shift of the TM 3d‐O 2p and non‐bonding O‐2p to lower energy, which would decrease Li+ diffusion activation energy and increase oxygen vacancy forming energy, finally improving the Li+ diffusion kinetics and stabilizing lattice oxygen. Moreover, the increased “LiOLi” configuration in the Li2MnO3 phase via increasing the Mn concentration can increase the reversible capacity to offset the negative effect of inactive doping and Li+/Ni2+ intermixing. This strategy of modulating the local electronic structure of LLOs provides great potential to design high‐energy‐density Li‐ion batteries.
The local electronic structure is modulated effectively via adjusting the local atomic coordination, triggering the TM 3d‐O 2p bands and non‐bonding O‐2p bands to lower energy. The low‐energy shift quickens the Li+ diffusion kinetics and stabilizes the lattice oxygen. As a result, outstanding electrochemical performance is achieved.
Metal–sulfur batteries exhibit great potential as next‐generation rechargeable batteries due to the low sulfur cost and high theoretical energy density. Sodium–sulfur (Na–S) batteries present higher ...feasibility of long‐term development than lithium–sulfur (Li–S) batteries in technoeconomic and geopolitical terms. Both lithium and sodium are alkali metal elements with body‐centered cubic structures, leading to similar physical and chemical properties and exposing similar issues when employed as the anode in metal–sulfur batteries. Indeed, some inspiration for mechanism researches and strategies in Na–S systems comes from the more mature Li–S systems. However, the dissimilarities in microscopic characteristics determine that Na–S is not a direct Li–S analogue. Herein, the daunting challenges derived by the differences of fundamental characteristics in Na–S and Li–S systems are discussed. And the corresponding strategies in Na–S batteries are reviewed. Finally, general conclusions and perspectives toward the research direction are presented based on the dissimilarities between both systems. This review attempts to provide important insights to facilitate the assimilation of the available knowledge on Li–S systems for accelerating the development of Na–S batteries on the basis of their dissimilarities.
Sodium–sulfur (Na–S) batteries present higher feasibility of long‐term development than lithium–sulfur (Li–S) batteries in technoeconomic and geopolitical terms. This review summarizes the daunting challenges derived by the differences of the fundamental characteristics in Na–S and Li–S batteries and corresponding strategies based on Na metal anode, electrolyte systems, and S cathode.
Potassium‐ion batteries (PIBs) are promising alternatives to lithium‐ion batteries because of the advantage of abundant, low‐cost potassium resources. However, PIBs are facing a pivotal challenge to ...develop suitable electrode materials for efficient insertion/extraction of large‐radius potassium ions (K+). Here, a viable anode material composed of uniform, hollow porous bowl‐like hard carbon dual doped with nitrogen (N) and phosphorus (P) (denoted as N/P‐HPCB) is developed for high‐performance PIBs. With prominent merits in structure, the as‐fabricated N/P‐HPCB electrode manifests extraordinary potassium storage performance in terms of high reversible capacity (458.3 mAh g−1 after 100 cycles at 0.1 A g−1), superior rate performance (213.6 mAh g−1 at 4 A g−1), and long‐term cyclability (205.2 mAh g−1 after 1000 cycles at 2 A g−1). Density‐functional theory calculations reveal the merits of N/P dual doping in favor of facilitating the adsorption/diffusion of K+ and enhancing the electronic conductivity, guaranteeing improved capacity, and rate capability. Moreover, in situ transmission electron microscopy in conjunction with ex situ microscopy and Raman spectroscopy confirms the exceptional cycling stability originating from the excellent phase reversibility and robust structure integrity of N/P‐HPCB electrode during cycling. Overall, the findings shed light on the development of high‐performance, durable carbon anodes for advanced PIBs.
A viable anode material composed of nitrogen/phosphorus co‐doped hollow porous bowl‐like hard carbon is developed for potassium ion batteries. The resulting anode manifests prominent merits in structure, endowing it with extraordinary K+ storage capability. The K+ storage mechanisms are revealed through in‐depth studies by combining in situ TEM studies, ex situ microscopic, and Raman spectroscopy in conjunction with DFT calculations.
Excessive use of agro-chemicals （such as mineral fertilizers） poses potential risks to soil quality. Application of organic amendments and reduction of inorganic fertilizer are economically feasible ...and environmentally sound approaches to de- velop sustainable agriculture. This study investigated and evaluated the effects of mineral fertilizer reduction and partial substitution of organic amendment on soil fertility and heavy metal content in a 10-season continually planted vegetable field during 2009-2012. The experiment included four treatments： 100% chemical fertilizer （CF100）, 80% chemical fertilizer （CF80）, 60% chemical fertilizer and 20% organic fertilizer （CF60＋OM20）, and 40% chemical fertilizer and 40% organic fertilizer （CF40＋OM40）. Soil nutrients, enzyme activity and heavy metal content were determined. The results showed that single chemical fertilizer reduction （CF80） had no significant effect on soil organic matter content, soil catalase activity and soil heavy metal content, but slightly reduced soil available N, P, K, and soil urease activity, and significantly reduced soil acid phosphatase activity. Compared with CF100, 40 or 60% reduction of chemical fertilizer supplemented with organic fertilizer （CF60＋OM20, CF40＋OM40） significantly increased soil organic matter, soil catalase activity and urease activity especially in last several seasons, but reduced soil available P, K, and soil acid phosphatase activity. In addition, continu- ous application of organic fertilizer resulted in higher accumulation of Zn, Cd, and Cr in soil in the late stage of experiment, which may induce adverse effects on soil health and food safety.
Considerable endeavors are developed to suppress lithium (Li) dendrites and improve the cycling stability of Li metal batteries in order to promote their commercial application. Herein, continuous ...zinc (Zn) nanoparticles‐assembled film with homogenous nanopores is proposed as a modified layer for separator via a scalable method. The in situ formed LiZn alloy film during initial Li plating can serve as a Li+ ion rectification and lithiophilic layer to regulate the nucleation and reverse deposition of Li. When applied in Li|LiFePO4 full cells with traditional carbonate‐based electrolyte, the modified separator enables outstanding cycling stability of up to 350 cycles without capacity loss at a large rate of 5 C (3.4 mA cm−2) and a remarkable reversible capacity of 144 mAh g−1 after 120 cycles at a commercial mass loading as high as 19.72 mg cm−2. The excellent electrochemical performances are ascribed to the dendrite‐free reverse Li deposition induced by modified layer by means of its lithiophilic property for regulating homogeneous Li nucleation on the separator as well as its well‐distributed nanopores for homogenizing Li+ ion flux and enhancing electrolyte wetting.
A zinc nanoparticles‐assembled film with even nanopores is modified on the surface of the separator to rectify Li+ ion flux and promote the dendrite‐free reverse lithium (Li) deposition. When applied in Li|LiFePO4 full cells with traditional carbonate‐based electrolyte, the modified separator enables outstanding cycling and rate performances at a cathode mass loading over 19.72 mg cm−2.
3D Graphene sheets encapsulated amorphous hollow CoSnO3 nanoboxes (H‐CoSnO3@reduced graphene oxide RGO) are successfully fabricated by first preparing 3D graphene oxides encapsulated solid CoSn(OH)6 ...nanocubes, followed by an alkaline etching process and subsequent heating treatment in Ar. The hollow CoSnO3 nanoboxes with average particle size of 230 nm are uniformly and tightly encapsulated by RGO sheets. As an anode material for Li‐ion batteries, H‐CoSnO3@RGO displays high initial Coulombic efficiency of 87.1% and large reversible capacity of 1919 mA h g−1 after 500 cycles at the current density of 500 mA g−1. Moreover, excellent rate capability (1250, 1188, 1141, 1115, 1086, 952, 736, and 528 mA h g−1 at 100, 200, 300, 400, 500, 1000, 2000, and 5000 mA g−1, respectively) is acquired. The reasons for excellent lithium storage properties of H‐CoSnO3@RGO are discussed in detail.
A hollow CoSnO3 nanobox encapsulated by graphene sheets results in a 3D interconnected conductive framework. The higher reversed conversion potential of metal Co can act as an anchor to prohibit the coarsening of Sn nanocrystals during delithiation. Combined with a hollow construction and amorphous features, the synthesized CoSnO3–graphene hybrid anode delivers high initial Coulombic efficiency, remarkable cycling, and rate properties.
An electrocatalyst with excellent performance is widely perceived as core materials to solve the practical application of lithium–oxygen batteries (LOBs). Vacancy/interfacial engineering can affect ...reaction intermediate adsorption and catalytic activity by manipulating the local electronic structure, which is key to improving the performance of LOBs. Here, MoO2‐supported Mo3P@Mo nanocomposites with phosphorus vacancy and interfacial contact are facile synthesized and used as the electrocatalyst to control the morphology of lithium peroxide (Li2O2) and to boost the electrochemical performance of LOBs. The nanocomposites exhibit excellent electrochemical performance with lower overpotential and super long cycling stability, can stably cycle for 500 cycles at 500 mA g−1 with a round‐trip efficiency close to 100%, and can work for 1370 h with failure at the lower cut‐off of 2 V. The influence of the interface and phosphorus vacancy, and the catalytic mechanism are explained by the result about first‐principles calculations and experimental studies.
MoO2‐supported Mo3P@Mo nanocomposites with phosphorus vacancy and interfacial contact exhibit excellent electrochemical performance with lower overpotential and super‐long cycling stability, can stably cycle for 500 cycles at 500 mA g−1 with a round‐trip efficiency close to 100%, and can work for 1370 h with failure at the lower cut‐off of 2 V.
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