Synergistic Structural Engineering of Tunnel‐Type Polyantimonic Acid Enables Dual‐Boosted Volumetric and Areal Lithium Energy Storage

Abstract

Tunnel‐structured polyantimonic acid (PAA) is an intriguing high‐capacity anode candidate for alkali‐metal‐ion storage; however, the awful electroconductivity of PAA (≈10–10 S cm–1) normally requires coupling with large‐surface‐area conductive substrate (e.g., graphene), conversely leading to poor scalability, ultralow density, and execrable volumetric energy. Synergistic structural engineering of PAA via bulk‐phase ion substitution and incorporation with low‐cost flake graphite (FG) is presented here to construct composite electrodes for lithium‐storage. The full‐occupation of Mn2+ into the tunnel‐centers of PAA synchronously improves its bulk conductivity (≈10–5 S cm–1) and true density (4.58 g cm–3), whilst less than 20% volume expansion of PAA is consequently achieved by FG confinement with enhanced multielectron‐reaction kinetics, unveiled by ex/in situ techniques. Besides delivering considerable volumetric capacity (>1200 mAh cm–3 at 0.1 A g–1), thus‐fabricated high‐tap‐density composite favors the construction of conducting additive‐free, high‐loading thick electrodes (>6.0 mg cm–2), exhibiting dual‐boosted areal/volumetric capacities (4.2 mAh cm–2/743 mAh cm–3), and fast‐charging capability (75% capacity charged within ≈13 min). Moreover, 3D‐printed composite electrodes with tunable shape and mass‐loading are also implemented to showcase impressive areal/volumetric Li+‐storage performance. Paring with high‐loading and high‐compact‐density LiCoO2 cathodes (e.g., 18.0 mg cm–2/3.53 g cc–1), full‐cells achieve remarkable electrode‐level areal‐/volumetric‐energy‐densities beyond 7.0 mWh cm–2/850 Wh L–1cathode+anode.

Rational Design of High‐Loading Electrodes with Superior Performances Toward Practical Application for Energy Storage Devices

“…[216] Wu et al also customized square and circular electrodes using 3D printing. [188] Moreover, porous 3D printing structures like grid, [217] cube, and block structures [219] have been explored. By combining micro/mesoporous materials in the ink formulation, hierarchical porous structures have been achieved, creating smooth transmission channels for electrons/ions and buffering volume expansion during cycling.…”

“…[186,187] 2) Metal heteroatom doping can adjust the Fermi level of the matrix materials, thereby improving intrinsic conductivity. [177,188] Both cobalt-modified carbon [76] and cobalt-doped electrocatalysts [177,184] have shown improvements in electrochemical performance. For instance, Li et al synthesized a cobalt-doped MoSe 2 /Ti 3 C 2 T x bifunctional catalyst as an efficient sulfur host.…”

Electrochemically Induced Crystalline‐to‐Amorphous Transition of Dinuclear Polyoxovanadate for High‐Rate Lithium‐Ion Batteries

“…The experiment details were discussed in reference. [41] High-resolution HAADF-STEM, STEM-IDPC, and EELS images were obtained with a Talos F200s microscope operated at 300 kV. The IDPC technique allowed imaging under low-dose conditions to avoid the irradiation effect of the crystal H 2 O molecules.…”

Space-Confined Nucleation of Semimetal-Oxo Clusters within a [H7P8W48O184]33– Macrocycle: Synthesis, Structure, and Enhanced Proton Conductivity

“…Polynuclear clusters or polymers constructed exclusively by oxyanions of group VA, namely, [X m O y ] n z – (X = P III/V , As III/V , and Sb III/V ) are of central importance in a variety of strategic fields. − Polyphosphates, for example, have long been put to wide use in water treatment, modified asphalt, and food additives . Meanwhile, polyantimonic acid and its derivatives can be harnessed for fire-proof materials, ion exchangers, and electrodes in Li-ion batteries. , However, the development of As III/V -oxo clusters or polyarsenates­(III/V) has been slower due to a lack of scientific research. , Beyond that, the structural evolution from monomeric oxyanions to condensed products noted above is still not well understood. In an effort to address these problems, controlled aggregation of semimetallic oxyanions within a structurally well-defined P 8 W 48 may help to visualize their preferred hydrolysis–condensation behaviors and spatial arrangements by X-ray crystallography and to lay structural foundations for taking the space-confined synthetic technique in POM chemistry a step further.…”

“…75 Meanwhile, polyantimonic acid and its derivatives can be harnessed for fire-proof materials, 76 ion exchangers, 77 and electrodes in Li-ion batteries. 78,79 However, the development of As III/V -oxo clusters or polyarsenates(III/V) has been slower due to a lack of scientific research. 80,81 Beyond that, the structural evolution from monomeric oxyanions to condensed products noted above is still not well understood.…”