Despite extensive studies on solvent effects in proton exchange membrane fuel cells (PEMFCs), the mechanistic role of solvent-component interactions in colloidal catalyst ink stabilization remains unsolved. Here, we systematically investigate alcohol/water mixed solvents to reveal a critical trade-off between electrostatic and hydrophobic forces. Our results demonstrate that lower solubility parameters (delta) and dielectric constants (epsilon) enhance ink stability, with isopropanol > 1-propanol > ethanol performance hierarchy. Increasing water content destabilizes the system, while unexpectedly, higher Zeta potential correlate with reduced stability. This paradox stems from sulfonic acid groups dissociation in high-epsilon solvents, which amplifies electrostatic repulsion but simultaneously strengthens hydrophobic attraction, ultimately dominating colloidal destabilization. Notably, in 1-propanol systems, elevated ionomer concentrations boost both zeta potential and stability, indicating synergistic electrostatic-hydrophobic regulation. Furthermore, ionomer-free inks retain stability through catalyst surface polar group hydrolysis. These findings establish hydrophobic interactions as the primary stability determinant and propose a solvent selection framework (delta, epsilon, polarity) for PEMFC manufacturing.

Aqueous Zn-S batteries face challenges in sulfur conversion reversibility and cathode stability. Here, we introduce a chemical confinement strategy using an alkene-containing Th-BE monomer to stabilize the sulfur cathode. Sulfur is chemically confined within the Th-BE framework through robust C-S bonds, enabling improved reaction reversibility and cycling stability.

Lithium-rich layered oxide cathode materials have a unique oxygen coordination environment, which allows oxygen anions to participate in the electrochemical reaction and provide more capacity. However, its surface TM dissolution and deterioration of the electrode/electrolyte interface during cycling lead the performance degradation. In this study, a robust hybrid coating strategy is proposed based on in-situ controllable surface chemistry reaction. The coating consists of lithiated phytate(LixPhA) and titanate coupling agent (201). Different from conventional coating, the robust hybrid coating is flexible, continuous and conductive. These advantages ensure the matching of Li1.2Ni0.2Mn0.6O2 surface and electrode/electrolyte interface ionic conductivity. Besides, the coating can reduce the air sensitivity of the material surface and its PO43- and -P2O7 can stabilize TM . Based on the optimal results, Li1.2Ni0.2Mn0.6O2 exhibits lower medium discharge voltage decay rate of 2.6 mV per cycle (3.3 mV per cycle before) during 300 cycles at 1 C (1 C = 250 mA g-1). And it also can maintain high discharge specific capacity, about 140 mAh g-1 at 5C. This surface modification strategy provides a new insight for Li-rich electrode/electrolyte interface stability via multifunctional surface chemistry design.

Benefited from its high process feasibility and controllable costs, binary-metal layered structured LiNi0.8Mn0.2O2 (NM) can effectively alleviate the cobalt supply crisis under the surge of global electric vehicles (EVs) sales, which is considered as the most promising next-generation cathode material for lithium-ion batteries (LIBs). However, the lack of deep understanding on the failure mechanism of NM has seriously hindered its application, especially under the harsh condition of high-voltage without sacrifices of reversible capacity. Herein, single-crystal LiNi0.8Mn0.2O2 is selected and compared with traditional LiNi0.8Co0.1Mn0.1O2 (NCM), mainly focusing on the failure mechanism of Co-free cathode and illuminating the significant effect of Co element on the Li/Ni antisite defect and dynamic characteristic. Specifically, the presence of high Li/Ni antisite defect in NM cathode easily results in the extremely dramatic H2/H3 phase transition, which exacerbates the distortion of the lattice, mechanical strain changes and exhibits poor electrochemical performance, especially under the high cutoff voltage. Furthermore, the reaction kinetic of NM is impaired due to the absence of Co element, especially at the single-crystal architecture. Whereas, the negative influence of Li/Ni antisite defect is controllable at low current densities, owing to the attenuated polarization. Notably, Co-free NM can exhibit better safety performance than that of NCM cathode. These findings are beneficial for understanding the fundamental reaction mechanism of single-crystal Ni-rich Co-free cathode materials, providing new insights and great encouragements to design and develop the next generation of LIBs with low-cost and high-safety performances.

The economically important tin -tungsten mineralization in southwestern China has attracted much interest in recent years, yet its age, tectonic setting, and genetic relationship to the host granites remain uncertain in most regions. Our focus in this study is the Shuicheng tin-polymetallic deposit, situated in the western sector of the Diantan Batholith, within the northern Tengchong Block. The granites in this area consist of two intrusive units, i.e., 1) biotite monzogranite (T1), with LA-ICP-MS zircon U - Pb ages ranging from 76.88 +/- 0.43 Ma to 74.69 +/- 0.57 Ma, whole-rock e Nd (t) values ranging from -9.75 to -8.11, and zircon e Hf (t) values from -12.19 to -8.85; and 2) alkali-feldspar granite (T2), with an LA-ICP-MS zircon U - Pb age of 52.16 +/- 0.23 Ma, whole-rock e Nd (t) values of -10.15 to -8.25, and zircon e Hf (t) values of -9.64 to -8.06. These two intrusive events have been linked to prolonged low-angle subduction and retreat of the subducting Neo-Tethys Ocean Plate, respectively. The Shuicheng granites exhibit high concentrations of SiO 2 and Al 2 O 3 , contrasted with low levels of FeO T , CaO, MgO, TiO 2 , and P 2 O 5 , suggesting that they are highly fractionated S -type granites. High abundances of Rb, K, U, and Hf, along with low contents of Ba, Sr, and Ti, further indicate significant fractionation and crystallization processes during magma evolution. Importantly, a transition from purely magmatic conditions to a magmatichydrothermal state occurred during the latter stages of magmatic evolution. This transition, associated with an amplified potential for tin mineralization, provides fresh insight into the role of magmatic processes in ore genesis, enriching our understanding of the tin -tungsten mineralization history of the Tengchong region.

Ni-rich layered oxides have the advantages of high energy density, long cycle life and environmental friendliness, which are considered among the most promising cathode materials for high energy density lithium-ion batteries (LIBs). However, problems such as humidity sensitivity, rapid capacity decay and thermal runaway greatly limit their potential applications. While it is widely accepted that the foreign-ion doping is an effective strategy to enhance cathode electrochemical properties, a comprehensive understanding of its functioning mechanisms and rational doping strategies for next generation Ni-rich cathodes are still lacking. In this review, the issues and challenges of Ni-rich layered oxides are thoroughly discussed. In addition, different mechanisms of elemental doping are systematically analyzed, including the pillar effect, the inhibition of Li/Ni mixing, the formation of surface coating, the change of particle morphology, the suppression of oxygen release and the generation of microcracks. Moreover, the characteristics and features of doping elements in different valence states are compared in detail. We also share our perspectives on key doping principles and future cathode designs. This review offers an exhaustive summary of the cathode doping strategies from doping mechanisms to valence states of doping elements, from historical experience to future design, and provides a fundamental understanding of doping modification for Ni-rich materials.

Ni-rich layered cathode materials are progressively considered as the standard configuration of high-energy electric vehicles by virtues of their high capacity and eliminated "range anxiety." However, the poor cyclic stability and severe cobalt supply crisis would restrain their wide commercial applicability. Here, a cost-effective single-crystal Co-free Ni-rich cathode material LiNi0.8Mn0.18Fe0.02O2 (NMF), which outperforms widely commercial polycrystalline LiNi0.83Co0.11Mn0.06O2 (MNCM) and single-crystal LiNi0.83Co0.11Mn0.06O2 (SNCM) is reported. Surprisingly, NMF can compensate for the reversible capacity loss under the designed conditions of high-temperature and elevated-voltage, achieving a competitive energy density compared with conventional MNCM or SNCM. Combining operando characterizations and density functional theory calculation, it is revealed that NMF cathode with improved dynamic structure evolution largely alleviates the mechanical strain issue commonly found in Ni-rich cathode, which can reduce the formation of intragranular cracks and improve the safety performance. Consequently, this new Co-free NMF cathode can achieve a perfect equilibrium between material cost and electrochemical performance, which not only reduces the production cost by >15%, but also demonstrates excellent thermal stability and cycling performance..

Increasing demand for electric vehicles (EVs) worldwide and the requirements for environmental protection have greatly promoted the development of low-Co, Ni-rich layered cathodes due to their high energy density, reasonable cost, and less environmental pollution. Nevertheless, serious performance degradation and safety concerns resulting from structural/interfacial instability under high operating voltages (>= 4.3 V) have greatly hindered its commercialization. Herein, we propose a feasible surface modification strategy by introducing a multifunctional Li2SiO3 (LSO) coating layer onto the surface of Co less single-crystalline LiNi0 center dot 63Co0 center dot 07Mn0 center dot 3O2 (NCM) to solve the above challenges. The uniform Li2SiO3 coating layer has a unique three-dimensional (3D) ion diffusion channel, which greatly promotes the transmission of Li+ and alleviates interfacial stress accumulation. Equally important, the electrochemically inert Li2SiO3 coating layer has a stable structure framework with strong Si-O bonds, which inhibit anisotropic particle volume expansion and the occurrence of side reactions during long-term cycling. As a consequence, LSO modified NCM exhibits greatly improved electrochemical properties even at harsh testing conditions and achieves capacity retention of 79.1% after 200 cycles at 25.C-circle within 2.95-4.5 V in half cells. Furthermore, it provides an outstanding capacity retention of 94.7% after 300 cycles at 25.C-circle within 2.95-4.4 V when tested in pouch full cells.

As a promising high energy density cathode, single-crystal Ni-rich cathode face poor diffusion dynamics, which leads to poor structural evolution, poor cyclic stability and unfavorable rate performance, thus impeding its wider application. Herein, the strategy of synergistic surface modification by ionic conductor coating and trace element doping is delicately designed. The surface protective Li3BO3 layer is wrapped on the single-crystal LiNi0.83Co0.11Mn0.06O2 (NCM83), which can improve the compatibility of cathode/electrolyte with reduced interface resistance. While Zr is incorporated into bulk to stabilize the crystal structure and migration channel. This synergistic strategy achieves the improvement of ionic transport and structural stability of single-crystal NCM83 (Zr-NCM83@B) from the outer surface to the inner body. As expected, the modified cathode Zr-NCM83@B demonstrates a satisfying electrochemical performance. It delivers a high reversible capacity of 169 mAh g-1 in coin-type half-cell at 4C within 3.0-4.3 V. Remarkably, it displays excellent capacity retention of 83.5 % in Zr-NCM83@B || graphite pouch-type full-cell over 1400 cycles at 1C with high voltage range of 2.8-4.4 V. This synergistic surface modification provides a reference for commercial development of advanced single-crystal Ni-rich cathode under harsh testing conditions. (c) 2022 Elsevier Inc. All rights reserved.

LiNi0.8Co0.1Mn0.1O2 (NCM811), a high nickel-positive electrode material, has higher discharge capacity, lower cost, and less environmental pollution than other systems, so it has attracted many people’s attention. However, its poor thermal stability, cycle rate performance, and safety problems limit its practical application. In this paper, the NCM811 cathode material with Al3+ and PO43− co-doping (NCM-PA) was prepared by co-precipitation method and high-temperature solid-state method to improve its properties. The results show that the co-doping can effectively inhibit the mixing of lithium and nickel, maintain the good lamellar structure of the cathode material, and improve the electrochemical performance of the cathode material. The capacity retention rate of NCM-PA is 14.1% higher than that of the raw material after 100 cycles at 1 C. In addition, due to the small degree of electrode polarization of the co-doping material, NCM-PA still has a discharge-specific capacity of 155.8 mAh/g when the current density is 5 C.

Yifei Zhou1, Wenfan Feng1, Yanbin Xu*,1, Xingang Liu1, Shuai Wang1, Zhiqiang Lv1, Xiao Li1, Ethan Burcar2, Zhe Wang*,2 and Zhenglong Yang*,1 1. School of Chemistry and Materials Science, Ludong University, Yantai 264025, PR China 2. Chemistry Department, Oakland University, Rochester, MI, 48309, USA

LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811), a high nickel-positive electrode material, has higher discharge capacity, lower cost, and less environmental pollution than other systems, so it has attracted many people’s attention. However, its poor thermal stability, cycle rate performance, and safety problems limit its practical application. In this paper, the NCM811 cathode material with Al 3+ and PO 4 3− co-doping (NCM-PA) was prepared by co-precipitation method and high-temperature solid-state method to improve its properties. The results show that the co-doping can effectively inhibit the mixing of lithium and nickel, maintain the good lamellar structure of the cathode material, and improve the electrochemical performance of the cathode material. The capacity retention rate of NCM-PA is 14.1% higher than that of the raw material after 100 cycles at 1 C. In addition, due to the small degree of electrode polarization of the co-doping material, NCM-PA still has a discharge-specific capacity of 155.8 mAh/g when the current density is 5 C.

NASICON-structured Ti-based polyanion compounds benefit from a stable structural framework, large ion channels, and fast ion mobility. However, the large radius of potassium and its poor electronic conductivity restrict its use in potassium-ion batteries. Herein, hierarchical mesoporous Mn0.5Ti2(PO4)3@C microspheres have been successfully synthesized using a simple electrospraying method. These microspheres consist of Mn0.5Ti2(PO4)3 nanoparticles evenly embedded in three-dimensional mesoporous carbon microspheres. The hierarchical mesoporous micro/nanostructure facilitates the rapid insertion and extraction of K+, while the three-dimensional carbon microspheres matrix enhances electrical conductivity and prevents active materials from collapsing during cycling. So the hierarchical mesoporous Mn0.5Ti2(PO4)3@C microspheres exhibit a high reversible discharge specific capacity (306 mA h g-1 at 20 mA g-1), a notable rate capability (123 mA h g-1 at 5000 mA g-1), and exceptional cycle performance (148 mA h g-1 at 500 mA g-1 after 1000 cycles). The results show that electrosprayed Mn0.5Ti2(PO4)3@C microspheres are a promising anode for PIBs.

Hybrid supercapacitors (HSCs) with large energy and power density have received increasing concern for their great potential in satisfying the requirements of energy storage systems. Nonetheless, the imbalanced kinetics between the sluggish battery-type cathode and the rapid capacitor-type anode make it difficult for HSCs to achieve high energy density at high power density. Herein, a novel N-doped carbon quantum dots/Ni-Co-Se (N- CQDs/Ni-Co-Se) hollow microspheres composite is synthesized via a facile hydrothermal approach using bifunctional CQDs as size regulators and conductive agents for the first time. Thanks to the synergism of highly conductive N-CQDs with rapid electron transfer and reduced-size hollow micro-/nanostructures contributing to the enhanced ion transport, the as-prepared battery-type N-CQDs/Ni-Co-Se hollow microspheres composite cathode exhibits admirable rate property. In-depth electrochemical kinetic analyses and density functional theory (DFT) calculations are utilized to elucidate the preeminent kinetic properties. Furthermore, a novel HSC is fabricated based on the N-CQDs/Ni-Co-Se hollow microspheres composite cathode with ultrafast electrochemical kinetics, displaying a high energy density of 23.1 Wh kg(-1) at a superb power density of 38.3 kW kg(-1). This encouraging work provides a good strategy to construct ultrahigh rate battery-type electrode materials with tunable size and component for simultaneously obtaining high energy/power density HSCs.

Improving the high-voltage stability of cathode materials is a new strategy to enhance the energy density of lithium-ion batteries (LIBs) in recent years. However, as a traditional cathode material, the low reversible capacity at high cut-off voltages (>= 4.3 V) greatly restricts the application of LiCoO2. Herein, we have rationally synthesized a novel single-crystalline LiNi0.55Co0.15Mn0.3O2 cathode material (Z-NCM@B) by using the synergistic effect of Zr-doping and B2O3-coating. Excitedly, the modified Z-NCM@B cathode material shows improved high-voltage stability and excellent long-term cycling performance. Furthermore, it is revealed that the stronger ZreO bond formed by Zr4+ dopant can stabilize the crystal structure and promote the migration of Li+ in the cathode materials. Meanwhile, the uniform B2O3 coating layer effectively suppresses the material corrosion by electrolyte and reduces the loss of transition metal ions during the charge/ discharge cycle process. As anticipated, the Z2-NCM@B2 || graphite pouch-type full cell exhibits an advanced capacity retention of 96.9% over 250 cycles at an operating voltage of 4.2 V, while the capacity retention of the pristine NCM is only 88%. Besides, the Z2-NCM@B2 coin-cell retains a discharge capacity of 145.2 mA h g(-1) at 1 C with a satisfactory capacity retention of 79.2% after 100 cycles within a broad voltage range between 2.95 and 4.7 V, which is much superior than that for the pristine NCM (130.9 mA h g(-1), 70.9%). This synergistic modification strategy offers a reference for the practical application of NCM cathode materials with high-voltage stability and long-term cycling performance in LIBs. (C) 2022 Elsevier B.V. All rights reserved.

MnO2 has recently received great concern as a cathode material for zinc-based energy storage owing to its many advantages. Unfortunately, the low rate capability and poor cyclability hinder its practical application. Herein, novel layered MnO2 nanodots (delta-MnO2 NDs) are synthesized by a facile redox reaction, and utilized as the cathode for aqueous zinc-ion batteries/hybrid capacitors (ZIBs/ZICs) for the first time. Benefiting from the layered structure and nanoscale size, the delta-MnO2 NDs//Zn ZIBs display a considerable specific capacity of 335 mAh g(-1) at 0.1 A g(-1) , an impressive rate capacity of 125 mAh g(-1) at 2.0 A g(-1) , a large specific energy (466.7 Wh kg(-1) at 139 W kg(-1)), and a superior durability with 86.2% capacity retention after 1000 cycles at 1.0 A g(-1) . Further, the H+/Zn2+ co-insertion energy storage mechanism of the delta-MnO2 NDs cathode is verified by electrochemical kinetics analyses and ex-situ characterizations. Simultaneously, the novel ZICs based on delta-MnO2 NDs cathode exhibit a high specific energy of 68.7 Wh kg(-1 )and a satisfactory cycle life with 86.9% capacity retention after 5000 cycles at 1.0 A g(-1) . The quantization design strategy opens a new gateway for the design and exploitation of advanced cathodes for aqueous ZIBs and ZICs.

LiNi0.8Co0.1Mn0.1O2 has been regarded as a promising cathode material due to its high discharge capacity, but it suffers from structural instability during the cycling process. Here, Mg2+ and Al3+ are co-doped in LiNi0.8Co0.1Mn0.1O2 to ameliorate the problem. The analysis results reveal that the dual doping can enlarge the Li+ diffusion channel, lower Li+/Ni2+ disorder, and depress the structural degradation during cycling. Therefore, the electrochemical performance of cathode material with Mg2+ and Al3+ dual doping has been effectively enhanced. In the voltage range of 2.8–4.3 V, the discharge capacity of NCM-MA is 138.8 mAh g−1 after 200 cycles at 1 C, which is 31 mAh g−1 higher than the pristine NCM. Prolonging the cycles to 450 times, the capacity retention is 12.5% higher than the pristine material. Besides, the NCM-MA delivers a high discharge capacity of 150.33 mAh g−1 at 5 C, due to the improvement of Li+ diffusion kinetics.

The rapid development of bimetallic-based materials (BTMs) in lithium ion battery (LIB) is mainly attributed to its synergistic effect and multi-component flexibility, but it still has huge challenge due to the unstable cycling performance, poor conductivity and understanding of additional capacity. In this paper, zinc atom-doped NiO-MnCo2O4 matrix (NZ-MC) with double heterostructure is prepared, and then the dispersed carbon nanotube (CNT) is compounded to construct 3D conductive network hybrid (NZ-MC@CNT), which can be served as excellent anode electrode for energy storage. Optimized NZ-MC@CNT has reversible discharge of 862.1 mA h g(-1) at the higher current density 5 A g(-1) after 20 00 cycles and the superior rate capability of 818.2 mA h g(-1) at 12 A g(-1). Based on the detailed phase transition analysis and kinetic analysis, the high-energy application of optimized NZ-MC@CNT is mainly attributed to the outstanding pseudocapacitance at the region of double heterogeneous interface, thereby accelerating the reaction kinetics process. Mainwhile, the theoretical calculation and kinetics analysis are performed to deeply reveal the (de)lithiation pathways related to the energy storage mechanism about excellent electrochemical performance. In addition, NZ-MC@CNT was saved for different energy storage systems (LIBs/LICs/Li-DIBs) and present excellent performance, which further demonstrates the application potentiality of NZ-MC@CNT. (C) 2021 Elsevier Ltd. All rights reserved.

High-nickel ternary material LiNixCoyMn1-x-yO2 (NCM) as a cathode material of Li-ion batteries has already been applied in many fields, like electric vehicles and 3C, due to its low cost and outstanding energy storage performance. but fast capacity decays result from interfacial degradation and internal destruction of the NCM structure leading to poor cycle life during charge-discharge processes, hindering widespread application. To solve these problems, this work develops a modification scheme to achieve the one-step generation of a Li2MoO4 coating on the outside of LiNi0.83Co0.11Mn0.06O2 particles and dope high-valence cations (Mo6+) inside LiNi0.83Co0.11Mn0.06O2 while reducing the residual Li content on the outside of materials. At 1C(1C = 200mAhg(-1)), the modified sample, Mo + NCM-1.0 (1.0 mol% doped LiNi0.83Co0.11Mn0.06O2), exhibits an excellent discharge capacity of 202 mAhg(-1) and cycling stability with a capacity retention of 90.22%. By contrast, pristine LiNi0.83Co0.11Mn0.06O2 shows the discharge capacity is 189.27 mAhg(-1) with a capacity retention of 87.93%. Further research shows that the modification scheme can alleviate the electrode loss during cycling, stabilize the internal structure of the NCM, enhance the Li+ diffusion rate, and improve the electrochemical properties. This modification strategy can be applied to other cathode materials.

We summarized the recent progress of cathode materials used for SIBs and modified strategies, expecting to give an inspiration for the development of high-performance cathode materials.