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Results for “ultrahigh capacity”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Ultrahigh-Capacity Rocksalt Cathodes Enabled by Cycling-Activated Structural Changes

Mn-redox-based oxides and oxyfluorides are considered the most promising earth-abundant high-energy cathode materials for next-generation lithium-ion batteries. While high capacities are obtained in high-Mn content cathodes such as Li- and Mn-rich layered and spinel-type materials, local structure changes and structural distortions ( often lead to voltage fade, capacity decay, and impedance rise, resulting in unacceptable electrochemical performance upon cycling. In the present study, structural transformations that exploit the high capacity of Mn-rich oxyfluorides while enabling stable cycling, in stark contrast to commonly observed structural changes that result in rapid performance degradation, are reported. Here, it is shown that upon cycling of a cation-disordered rocksalt (DRX) cathode (Li 1.1 Mn 0.8 Ti 0.1 O 1.9 F 0.1 , an ultrahigh capacity of ≈320 mAh g –1 (energy density of ≈900 Wh kg –1 ) can be obtained through dynamic structural rearrangements upon cycling , along with a unique voltage profile evolution and capacity rise. At high voltage, the presence of Mn 4+ and Li + vacancies promotes local cation ordering, leading to the formation of domains of a “δ phase” within the disordered framework. On deep discharge, Mn 4+ reduction, along with Li + insertion transform the structure to a partially ordered DRX phase with a β'-LiFeO 2 -type arrangement. At the nanoscale, domains of the in situ formed phases are randomly oriented, allowing highly reversible structural changes and stable electrochemical cycling. These new insights not only help explain the superior electrochemical performance of high-Mn DRXbut also provide guidance for the future development of Mn-based, high-energy density oxide, and oxyfluoride cathode materials.

25 ENERGY STORAGE↗
DOE OSTI2022

A two-electron transfer mechanism of the Zn-doped δ-MnO 2 cathode toward aqueous Zn-ion batteries with ultrahigh capacity

Neutral aqueous zinc-ion batteries (ZIBs) have attracted considerable attention due to their safe and green features. As one typical cathode, birnessite MnO 2 (δ-MnO 2 ) suffers from low conductivity and structural instability, and its energy storage mechanism is still not well established yet. Herein, we developed a Zn-doped δ-MnO 2 material via a facile and effective microwave-assisted method for the cathode in aqueous ZIBs. By incorporating Zn to modify the microstructure and promote reaction kinetics, the Zn-doped δ-MnO 2 electrode demonstrates significantly enhanced electrochemical performance with an ultrahigh reversible capacity of 455 mA h g –1 and excellent specific energy of 628 W h kg –1 . In addition, the successive insertion of H + and Zn 2+ and deep two-electron transfer routes are revealed systematically by ex situ experiments. In this study, the two-electron transfer route (Mn 4+ /Mn 3+ and Mn 3+ /Mn 2+ ) mechanism of Zn-doped δ-MnO 2 electrodes explains the exceedingly high capacity and opens new opportunities to develop high-energy aqueous ZIBs.

25 ENERGY STORAGE↗
DOE OSTI2024

Mechanochemically Robust LiCoO 2 with Ultrahigh Capacity and Prolonged Cyclability

Pushing intercalation-type cathode materials to their theoretical capacity often suffers from fragile Li-deficient frameworks and severe lattice strain, leading to mechanical failure issues within the crystal structure and fast capacity fading. This is particularly pronounced in layered oxide cathodes because the intrinsic nature of their structures is susceptible to structural degradation with excessive Li extraction, which remains unsolved yet despite attempts involving elemental doping and surface coating strategies. Herein, a mechanochemical strengthening strategy is developed through a gradient disordering structure to address these challenges and push the LiCoO 2 (LCO) layered cathode approaching the capacity limit (256 mAh g -1 , up to 93% of Li utilization). This innovative approach also demonstrates exceptional cyclability and rate capability, as validated in practical Ah-level pouch full cells, surpassing the current performance benchmarks. Comprehensive characterizations with multiscale X-ray, electron diffraction, and imaging techniques unveil that the gradient disordering structure notably diminishes the anisotropic lattice strain and exhibits high fatigue resistance, even under extreme delithiation states and harsh operating voltages. Consequently, this designed LCO cathode impedes the growth and propagation of particle cracks, and mitigates irreversible phase transitions. In conclusion, this work sheds light on promising directions toward next-generation high-energy-density battery materials through structural chemistry design.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Fast-Charging and Ultrahigh-Capacity Lithium Metal Anode Enabled by Surface Alloying

Li metal anodes are going through a great revival but they still encounter grand challenges. One often neglected issue is that most reported Li metal anodes are only cyclable under relatively low current density (<5 mA cm -2 ) and small areal capacity (<5 mAh cm -2 ), which essentially limits their high-power applications and results in ineffective Li utilization (<1%). Herein, it is reported that surface alloyed Li metal anodes can enable reversible cycling with ultrafast rate and ultralarge areal capacity. Low-cost Si wafers are used and are chemically etched down to 20-30 mu m membranes. Simply laminating a Si membrane onto Li foil results in the formation of LixSi alloy film fused onto Li metal with mechanical robustness and high Li-ion conductivity. Symmetric cell measurements show that the surface alloyed Li anode has excellent cycling stability, even under high current density up to 25 mA cm -2 and unprecedented areal capacity up to 100 mAh cm -2 . Furthermore, the surface alloyed Li anode is paired with amorphous MoS 3 cathode and achieves remarkable full-cell performance.

36 MATERIALS SCIENCE↗
DOE OSTI2021

On the crystallography and reversibility of lithium electrodeposits at ultrahigh capacity

Abstract Lithium metal is a promising anode for energy-dense batteries but is hindered by poor reversibility caused by continuous chemical and electrochemical degradation. Here we find that by increasing the Li plating capacity to high values ( e.g ., 10–50 mAh cm −2 ), Li deposits undergo a morphological transition to produce dense structures, composed of large grains with dominantly (110) Li crystallographic facets. The resultant Li metal electrodes manifest fast kinetics for lithium stripping/plating processes with higher exchange current density, but simultaneously exhibit elevated electrochemical stability towards the electrolyte. Detailed analysis of these findings reveal that parasitic electrochemical reactions are the major reason for poor Li reversibility, and that the degradation rate from parasitic electroreduction of electrolyte components is about an order of magnitude faster than from chemical reactions. The high-capacity Li electrodes provide a straightforward strategy for interrogating the solid electrolyte interphase (SEI) on Li —with unprecedented, high signal to noise. We find that an inorganic rich SEI is formed and is primarily concentrated around the edges of lithium particles. Our findings provide straightforward, but powerful approaches for enhancing the reversibility of Li and for fundamental studies of the interphases formed in liquid and solid-state electrolytes using readily accessible analytical tools.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2025

Perspectives of active Si photonics devices for data communication and optical sensing

Si photonics has made rapid progress in research and commercialization in the past two decades. While it started with electronic–photonic integration on Si to overcome the interconnect bottleneck in data communications, Si photonics has now greatly expanded into optical sensing, light detection and ranging (LiDAR), optical computing, and microwave/RF photonics applications. From an applied physics point of view, this perspective discusses novel materials and integration schemes of active Si photonics devices for a broad range of applications in data communications, spectrally extended complementary metal–oxide–semiconductor (CMOS) image sensing, as well as 3D imaging for LiDAR systems. We also present a brief outlook of future synergy between Si photonic integrated circuits and Si CMOS image sensors toward ultrahigh capacity optical I/O, ultrafast imaging systems, and ultrahigh sensitivity lab-on-chip molecular biosensing.

electronic band structure↗
DOE OSTI2021

Oxygen redox chemistry in P2-Na 0.6 Li 0.11 Fe 0.27 Mn 0.62 O 2 cathode for high-energy Na-ion batteries

Owing to the abundance of raw material reserves and low cost, Na-ion batteries (NIBs) have successfully gained widespread attention from academic and industrial communities in the past few decades. However, the insufficient cathode energy density is still one of the critical bottlenecks restricting the development of NIBs. Following a strategy of introducing Li+ into the transition-metal (TM) layer to enhance the oxygen redox reaction, a novel layered cathode material P2-Na 0.6 Li 0.11 Fe 0.27 Mn 0.62 O 2 (NLFMO) was designed and successfully synthesized. This NLFMO cathode not only delivers a large initial reversible capacity of 207.3 mA h g -1 , but also shows a good cycling performance (104.2 mA h g -1 after 80 cycles) and rate capability (126.2 mA h g -1 at 1C). The ultrahigh capacity is contributed by both cationic (Fe 3+ /Fe 4+ and Mn 3+ /Mn 4+ ) and partially reversible anionic redox (O 2- /O n- ) reactions, revealed by in situ X-ray absorption spectroscopy (XAS) and X-ray photoelectron spectroscopy (XPS) techniques. Moreover, no detrimental P2–O2 phase transition was observed in ex situ X-ray diffraction (XRD) patterns, confirming the high structural stability during Na + deintercalation/intercalation processes. These results provide valuable information about the high-energy density layered cathode materials based on anionic redox reactions for NIBs.

25 ENERGY STORAGE↗
DOE OSTI2025

Interface‐Controlled Redox Chemistry in Aqueous Mn 2 ⁺/MnO₂ Batteries

Manganese dioxide (MnO 2 ) deposition/dissolution (Mn 2+ /MnO 2 ) chemistry, involving a two-electron-transfer process, holds promise for safe and eco-friendly large-scale energy storage. However, challenges like electrode/electrolyte interface environment fluctuations (H + and H 2 O activity), irreversible Mn degradation, and limited understanding of degradation mechanisms hinder the reversibility of the Mn 2+ /MnO 2 conversion. This study demonstrates a vanadyl/pervanadyl (VO 2+ /VO 2 + ) redox-mediated interface designed for high-energy Mn 2+ /MnO 2 batteries. Unlike flow systems, this work uncovers, for the first time, the mechanism of a static redox-mediated interface in regulating interfacial H + and H 2 O activities. Significantly, the VO 2+ /VO 2 + chemical redox mediation targets Mn 3+ intermediates, suppressing their hydrolysis and enabling 100% Mn 2+ /MnO 2 conversion. The redox-mediated interface enhances the Mn redox electron transfer process, achieving a stable ≈95% coulombic efficiency and ultrahigh capacity of 100 mAh cm −2 with an areal energy density of 111 mWh cm −2 , outperforming flow systems. The electrode also exhibits an average specific capacity of 593 mAh g −1 , approaching the theoretical limit of 616 mAh g −1 , and a specific energy density of 721 Wh kg −1 at high MnO 2 loadings (50–150 mg cm −2 ). Furthermore, the findings highlight the critical role of interfacial redox mediation in regulating H + and H 2 O activities and underscore the significance of interface dynamics.

Xue, Xinzhe [University of California, Santa Cruz,↗
DOE OSTI2022

Insights into the Crossover Effects in Cells with High‐Nickel Layered Oxide Cathodes and Silicon/Graphite Composite Anodes

Abstract Silicon anodes are regarded as one of the most promising alternatives to graphite (Gr) anodes due to their ultrahigh capacity, abundance, and low cost. Coupling Si‐based anodes with high‐nickel layered oxide cathodes LiNi x Mn y Co 1− x − y O 2 (NMC, x ≥ 0.8) can enhance the driving range for electric vehicles. Transition‐metal (TM) ion dissolution and deposition has been a long‐known failure mode for Gr‐based lithium‐ion batteries. However, the mechanistic insight associated with TM ion deposition on Si‐based anodes has rarely been reported. Herein, the impact of in situ deposited TM ions on SiO x /Gr composite anodes and the individual influences of Ni, Mn, and Co on the structural and electrochemical stability along with the underlying degradation mechanisms are presented. TM ion dissolution causes a greater deleterious impact on Si than on Gr, with different TM ions exhibiting different influences on anode‐electrolyte interphase formation. Specifically, Ni deposit induces more aggressive salt decomposition; Co deposit has negligible effect on salt decomposition, but significantly accelerates solvent decomposition; and Mn deposit aggravates both salt and solvent decompositions, resulting in worse full cell performance. The extent of degradation decreases in the order Mn 2+ > Ni 2+ > Co 2+ . The systematic comparisons presented can guide further development of high energy systems.

Zhang, Xianhui↗
DOE OSTI2022

Elastic Lattice Enabling Reversible Tetrahedral Li Storage Sites in a High-Capacity Manganese Oxide Cathode

The key to breaking through the capacity limitation imposed by intercalation chemistry lies in the ability to harness more active sites that can reversibly accommodate more ions (e.g., Li + ) and electrons within a finite space. However, excessive Li-ion insertion into the Li layer of layered cathodes results in fast performance decay due to the huge lattice change and irreversible phase transformation. Here, in this study, an ultrahigh reversible capacity is demonstrated by a layered oxide cathode purely based on manganese. Through a wealth of characterizations, it is clarified that the presence of low-content Li 2 MnO 3 domains not only reduces the amount of irreversible O loss; but also regulates Mn migration in LiMnO 2 domains, enabling elastic lattice with high reversibility for tetrahedral sites Li-ion storage in Li layers. This work utilizes bulk cation disorder to create stable Li-ion-storage tetrahedral sites and an elastic lattice for layered materials, with a reversible capacity of 600 mA h g –1 , demonstrated in th range 0.6–4.9 V versus Li/Li + at 10 mA g –1 . Admittedly, discharging to 0.6 V might be too low for practical use, but this exploration is still of great importance as it conceptually demonstrates the limit of Li-ions insertion into layered oxide materials.

25 ENERGY STORAGE↗
DOE OSTI2025

High‐Performance Rechargeable Lithium‐Chlorine Batteries with ALD Conformal Starburst Porous Graphene Positive Electrodes

Abstract Rechargeable alkali metal‐chlorine batteries are emerging as a promising high‐energy‐density solution. However, they confront significant challenges, including the primary issue stemming from the weak binding affinity of cathode materials for Cl 2 , which leads to a sluggish and inadequate supply of Cl 2 during the redox reactions, resulting in a shortened cycle life and low Coulombic efficiency (CE), particularly when operating at ultrahigh specific capacity outputs. Herein, an Al 2 O 3 ‐skinned heterostructured starburst porous graphene with conformal metasurfaces (Al 2 O 3 @rGO) is reported, crafted from a hierarchical porous starburst graphene arranged in a unique layered structure by the PTFE microemulsion skin effect, leveraging subsequent fluidized bed atomic layer deposition (FBALD) of Al 2 O 3 groups. Al 2 O 3 @rGO features superhydrophilicity, effective adsorption, fast kinetics from stable dynamic respiratory interface, high electrical and thermal conductivity anisotropy, intelligent thermal management and safe operation over a wide temperature range. Consequently, the Li‐Cl 2 @Al 2 O 3 @rGO battery achieves an ultrahigh discharge specific capacity of 5000 mAh g −1 at ≈100% CE, and even delivers stable cycling over 200 cycles with 2000 mAh g −1 at an average CE of 99.8% under low temperature environment of ‐40 °C. The scalable heterostructure approach offers a sustainable perspective of the development of functionalized metamaterials and metasurfaces for next‐generation safe and energy‐dense batteries and broader applications.

Chemistry↗
DOE OSTI2022

Direct Ink Writing of 3D Zn Structures as High‐Capacity Anodes for Rechargeable Alkaline Batteries

The relationship between structure and performance in alkaline Zn batteries is undeniable, where anode utilization, dendrite formation, shape change, and passivation issues are all addressable through anode morphology. While tailoring 3D hosts can improve the electrode performance, these practices are inherently limited by scaffolds that increase the mass or volume. Herein, a direct write strategy for producing template‐free metallic 3D Zn electrode architectures is discussed. Concentrated inks are customized to build designs with low electrical resistivity (5 × 10 −4 Ω cm), submillimeter sizes (200 μm filaments), and high mechanical stability (Young's modulus of 0.1–0.5 GPa at relative densities of 0.28–0.46). A printed Zn lattice anode versus NiOOH cathode with an alkaline polymer gel electrolyte is then demonstrated. This Zn||NiOOH cell operates for over 650 cycles at high rates of 25 mA cm −2 with an average areal capacity of 11.89 mAh cm −2 , a cumulative capacity of 7.8 Ah cm −2 , and a volumetric capacity of 23.78 mAh cm −3 . A thicker Zn anode achieves an ultrahigh areal capacity of 85.45 mAh cm −2 and a volumetric capacity of 81.45 mAh cm −3 without significant microstructural changes after 50 cycles.

25 ENERGY STORAGE↗
DOE OSTI2025

Five-volt-class high-capacity all-solid-state lithium batteries

Advances in battery technology have been impeded by the voltage constraints of electrolytes. Here, in this study, we present a high-energy all-solid-state battery design featuring >5 V operation and an ultrahigh areal capacity of 35.3 mAh cm −2 ; these attributes were enabled by a highly conductive and ultrahigh-voltage stable fluoride solid electrolyte, LiCl–4Li 2 TiF 6 (1.7 × 10 −5 S cm −1 at 30 °C). LiCl–4Li 2 TiF 6 shields high-voltage spinel oxide cathodes, achieving 106 mAh g −1 at 2C with 75.2% retention over 500 cycles for LiNi 0.5 Mn 1.5 O 4 , sharply contrasting with the conventional LiNbO 3 counterpart, which decomposes and fails to prevent detrimental interfacial degradation. The efficacy of LiCl–4Li 2 TiF 6 is validated across various systems, including LiCoMnO 4 , LiFe 0.5 Mn 1.5 O 4 and pouch-type LiNi 0.5 Mn 1.5 O 4 ||Li (or Ag–C) all-solid-state batteries, and further demonstrated by operability down to 2.3 V with 258 mAh g −1 and ultrathick 1.8-mm electrodes. This shielding layer with >5 V stability introduces a transformative design paradigm by revisiting the previously forbidden high-voltage cathodes.

36 MATERIALS SCIENCE↗