Anchoring Metal‐Organic Framework‐Derived ZnTe@C onto Elastic Ti₃C₂T_x MXene with 0D/2D Dual Confinement for Ultrastable Potassium‐Ion Storage

Abstract

Li-ion batteries (LIBs), the dominant electrochemical energy storage technology in the marketplace, are nevertheless not a good candidate for grid energy storage because of their high cost. In this sense, K-ion batteries (KIBs) have emerged as a reliable alternative to LIBs in grid energy storage because potassium is earth-abundant and cost-effective. [3][4][5][6][7] In addition, potassium has a similar standard electrode potential to lithium (K + /K vs Li + /Li: −2.93 vs −3.04 V against the standard hydrogen electrode, SHE), indicating that KIBs have high energy density. [6] Moreover, potassium has similar chemical properties to lithium, making it possible for the commercialized anode materials of LIBs, graphite, to be used directly for KIBs. Unfortunately, graphite only delivers a low theoretical capacity of 279 mAh g −1 for K + intercalation by forming KC 8 due to the sizeable K + radius (K + vs Li + : 1.38 vs 0.76 Å) and sluggish K + diffusion. [7,8] In this circumstance, developing advanced KIB anode materials with high capacity and favorable K + diffusion remains a significant challenge. Recently, transition metal dichalcogenides, such as oxides, [9] sulfides, [10][11][12][13][14][15] selenides, [16,17] and tellurides, [18][19][20][21][22] have been proposed for K + storage because they have high theoretical capacities. Compared to the oxide, sulfide, and selenide counterparts, transition metal tellurides (TMTs) exhibit several appealing advantages: higher conductivity for quick electron mobility, larger lattice spacings for enhanced K + diffusion, higher density for improved volumetric capacities, and metallic thermal conductivity for adequate joule heat transport during cycling. [23] These merits make TMTs an attractive and emerging candidate for K + storage. To date, several TMTs have been reported as KIB anode materials, including CoTe 2 , Bi 2 Te 3 , MoTe 2 , and WTe 2 . [18][19][20][21]24] However, two critical limitations hinder their practical implementations. The primary one is that they are not thermodynamically favorable for reacting with K + . Table S1 (Supporting Information) lists various metal−tellurium (MT) bonds and their dissociation energies. Most of the reported TMTs have large bond dissociation energies (>200 kJ mol −1 ), indicating that more energy is needed to break the MT bonds

Comprehensively Understanding the Role of Anion Vacancies on K‐Ion Storage: A Case Study of Se‐Vacancy‐Engineered VSe 2

“…This phenomenon can be attributed to the electrochemical activation by K‐bis(fluorosulfonyl) imide (KFSI)‐based electrolyte, which can decrease the charge transfer resistance with the GCD cycling tests (as shown later in Figure c). [ 34 ] In addition, slight capacity fluctuations are observed at the beginning stage of long‐term cycling tests. Other reported works also observed these fluctuations, in which KFSI‐based electrolytes were used.…”

“…[22] Subsequently, a noticed plateau at 0.25 V emerges but disappears in the following discharging curves, corresponding to the formation of solid electrolyte interphase (SEI) layer. [34,35] In the charging processes, two inconspicuous plateaus are observed at 1.58 and 2.50 V, ascribed to the reverse conversion reaction [2K 2 Se + V → K y VSe 2 + (4−y)K + + (4−y)e − ] and K + de-intercalation (K y VSe 2 → VSe 2 + yK + + ye − ), respectively. [22] Similar GCD behaviors are noticed in the case of P-VSe 2−x (Figure 2b), implying that introducing Se vacancies does not change the K + storage mechanism of VSe 2 .…”

“…Other reported works also observed these fluctuations, in which KFSI-based electrolytes were used. [34,46,47] Despite the exact reasons being unknown, optimizing the electrolyte is essential for achieving more stable cycling capacities.…”

Floatable Cu2(OH)PO4/rGO Aerogel for Full Spectrum Driven Photocatalytic Degradation of Organic Pollutants

“…Unfortunately, narrow bandgap semiconductors suffer from low carrier separation efficiency and short carrier lifetime due to the limitation of Coulombic interactions between electrons and holes, limiting the light utilization efficiency. , Very recently, low-dimensional heterostructures including 0D/2D, 1D/2D, and 2D/2D systems , have gained popularity due to the short-range interfacial interaction of two low-dimensional materials, which can promote electronic coupling and electron transfer. Among them, the 0D/2D heterostructure photocatalysts show excellent catalytic activities compared to their counterpart particles with a large size and broad size distribution. , For example, it was recently proven that the PbS@CdS@ZnS/g-C 3 N 4 0D/2D photocatalysts show broadband activity under UV, vis, and NIR light irradiation because the strong interaction yields efficient charge separation and transfer between them …”

Platinum Electrocatalyst Promoting Redox Kinetics of Li2S and Regulating Li2S Nucleation for Lithium–Sulfur Batteries

“…Nevertheless, the non-polarity of carbon materials limits their physical adsorption of LiPSs, making it challenging to combat rapid capacity loss during extended cycling. The introduction of metal compounds, such as oxides, [9] nitrides, [10] sulfides, [11] borides, [12] MXene, [13] and phosphides, [14] into carbon materials has proven to be an effective solution. Li et al [15] prepared Fe/Fe 3 C-MWCNTs, which achieved an ultra-long cycle life of 1000 cycles with an extremely low capacity decay rate of 0.0496% per cycle.…”