ArticlePublisher preview available

Enabling Fast Na + Transfer Kinetics in the Whole‐Voltage‐Region of Hard Carbon Anodes for Ultrahigh Rate Sodium Storage

Wiley
Advanced Materials
Authors:
To read the full-text of this research, you can request a copy directly from the authors.

Abstract and Figures

Efficient electrode materials, that combine high power and high energy, are the crucial requisites of sodium-ion batteries (SIBs) which have unwrapped new possibilities in the areas of grid-scale energy storage. Hard carbons (HCs) are considered as the leading candidate anode materials for SIBs, however, the primary challenge of slow charge transfer kinetics at the low potential region (< 0.1 V) remains unresolved till date, and the underlying structure-performance correlation is under debate. Herein, we report ultrafast sodium storage in the whole-voltage-region (0.01-2 V) with the Na+ diffusion coefficient enhanced by 2 orders of magnitude (∼10-7 cm2 s-1 ) through rational deploying the physical parameters of HC using a ZnO assisted bulk etching strategy. We unveil that the Na+ adsorption energy (Ea ) and diffusion barrier (Eb ) are in a positive and negative linear relationship with the carbon p-band center, respectively, and balanced of Ea and Eb is critical in enhancing the charge storage kinetics. The charge storage mechanism in HCs is evidenced through comprehensive in(ex)-situ techniques. The as prepared HC microspheres deliver a record high rate performance of 107 mAh g-1 @ 50 A g-1 and unprecedented electrochemical performance at extremely low temperature (426 mAh g-1 @ -40°C). This article is protected by copyright. All rights reserved.
This content is subject to copyright. Terms and conditions apply.
2109282 (1 of 11) © 2022 Wiley-VCH GmbH
www.advmat.de
ReseaRch aRticle
Enabling Fast Na+ Transfer Kinetics in the Whole-Voltage-
Region of Hard-Carbon Anodes for Ultrahigh-Rate Sodium
Storage
Xiuping Yin, Zhixiu Lu, Jing Wang, Xiaochen Feng, Swagata Roy, Xiangsi Liu, Yong Yang,
Yufeng Zhao,* and Jiujun Zhang
X. P. Yin, Z. X. Lu, X. C. Feng, S. Roy, Y. F. Zhao, J. J. Zhang
College of Sciences & Institute for Sustainable Energy
Shanghai University
Shanghai 200444, China
E-mail: yufengzhao@shu.edu.cn
J. Wang
Key Laboratory of Applied Chemistry
Yanshan University
Qinhuangdao 066000, China
X. S. Liu, Y. Yang
State Key Laboratory for Physical Chemistry of Solid Surface
College of Chemistry and Chemical Engineering
Xiamen University
Xiamen 361005, China
The ORCID identification number(s) for the author(s) of this article
can be found under https://doi.org/10.1002/adma.202109282.
DOI: 10.1002/adma.202109282
able energy exploitation of renewable
sources.[1–3] However, SIBs have to deal
with various challenges including infe-
rior rate capability, and condescending
lifetime, which generally instigated by the
lack of appropriate electrode materials,
especially the anodes.[4–7] Hard carbons
(HCs) have attracted extensive attention
with suitable potential versus Na+/Na,
good structural stability, decent coulombic
eciency, superior reversible capacity etc.,
and are considered as the most feasible
anode materials for further commerciali-
zation.[8–10] Nevertheless, the unsatisfied
rate capability of HCs (generally <5 A g–1)
represents the primary constraint in their
practical applications, as well as the under-
lying structure–performance correlation is
a substance of controversial discussion.
Typical HCs comprise a large number
of short-range-ordered graphitic domains
and internal micropore domains (or voids
between graphitic domains).[11] The gra-
phitic-domain with proper interlayer dis-
tance and the internal-nanopore-domain are both believed to be
capable of accommodating sodium ions.[12–17] Classic charge/dis-
charge curves of HCs comprise a high-potential slope (>0.10V)
and a low-potential plateau (0.01–0.10V). Various mechanisms
have been proposed to explicate the charge-storage behavior at
dierent potential regions, yet no conclusive outcome has been
accomplished.[18–25] A few studies correlate the charge-storage
behavior with the interlayer distance (d002), concluding that
short range ordered graphitic layers with d of 0.36–0.40nm are
capable of storing Na+ ions through “interlayer intercalation,”
providing a high plateau capacity,[26–29] whereas some other
studies contemplate that the filling of Na ions (or clusters) into
the internal micropores (or voids between graphitic domains) is
responsible for the plateau capacity.[12,13,30–32]
Despite the diverse opinions on the charge-storage mecha-
nism, it is a well-established fact that the low potential pla-
teau region represents the rate-determining step for HCs.
Various studies have unveiled that, HCs with obvious plateau
below 0.10V, encounter a dramatic drop of Na+ diusion coef-
ficient.[21,28,33–35] Generally, the Na+ diusion coecient at the
sloping area (3.00–0.10 V) is between 10–11 and 10–9 cm2 s–1,
which is of two orders lower (10–13 to 10–10 cm2 s–1) at the plateau
Ecient electrode materials, that combine high power and high energy, are
the crucial requisites of sodium-ion batteries (SIBs), which have unwrapped
new possibilities in the areas of grid-scale energy storage. Hard carbons
(HCs) are considered as the leading candidate anode materials for SIBs,
however, the primary challenge of slow charge-transfer kinetics at the low
potential region (<0.1V) remains unresolved till date, and the underlying
structure–performance correlation is under debate. Herein, ultrafast sodium
storage in the whole-voltage-region (0.01–2V), with the Na+ diusion coef-
ficient enhanced by 2 orders of magnitude (10–7 cm2 s–1) through rationally
deploying the physical parameters of HCs using a ZnO-assisted bulk etching
strategy is reported. It is unveiled that the Na+ adsorption energy (Ea) and
diusion barrier (Eb) are in a positive and negative linear relationship with
the carbon p-band center, respectively, and balance of Ea and Eb is critical
in enhancing the charge-storage kinetics. The charge-storage mechanism
in HCs is evidenced through comprehensive in(ex) situ techniques. The
as prepared HCs microspheres deliver a record high rate performance of
107 mAh g–1 @ 50 A g–1 and unprecedented electrochemical performance at
extremely low temperature (426 mAh g–1 @ 40 °C).
1. Introduction
Sodium-ion batteries (SIBs), owing to the abundant and cheap
sodium resources, have been surfaced as the next generation
large-scale energy storage systems to support the sustain-
Adv. Mater. 2022, 34, 2109282
... Benefiting from the ideal structure, CTSFS 1300 has excellent LT performance (Figure 1f). More importantly, Yin et al. found that the carbon p-band center upholds a linear relationship with both the Na + adsorption energy (Ea) and diffusion energy barrier (Eb), which can be readily manipulated by adjusting the physical parameters of the hard carbons Nanomaterials 2024, 14, 1604 5 of 32 (HCs) [42]. They synthesized HC microspheres with a well-regulated microstructure via the ZnO-assisted bulk etching method ( Figure 1g). ...
... The application of hard carbon in SIBs at LTs is still worth exploring. the hard carbons (HCs) [42]. They synthesized HC microspheres with a well-regulated microstructure via the ZnO-assisted bulk etching method ( Figure 1g). ...
Article
Full-text available
Sodium-ion batteries (SIBs) have garnered significant interest due to their potential as viable alternatives to conventional lithium-ion batteries (LIBs), particularly in environments where low-temperature (LT) performance is crucial. This paper provides a comprehensive review of current research on LT SIBs, focusing on electrode materials, electrolytes, and operational challenges specific to sub-zero conditions. Recent advancements in electrode materials, such as carbon-based materials and titanium-based materials, are discussed for their ability to enhance ion diffusion kinetics and overall battery performance at colder temperatures. The critical role of electrolyte formulation in maintaining battery efficiency and stability under extreme cold is highlighted, alongside strategies to mitigate capacity loss and cycle degradation. Future research directions underscore the need for further improvements in energy density and durability and scalable manufacturing processes to facilitate commercial adoption. Overall, LT SIBs represent a promising frontier in energy storage technology, with ongoing efforts aimed at overcoming technical barriers to enable widespread deployment in cold-climate applications and beyond.
Article
Full-text available
The sodium storage behavior in the plateau region is crucial for determining the capacity and rate capability of hard carbon (HC) anodes in sodium‐ion batteries (SIBs). Key structural features for achieving excellent plateau performance include extended graphite domains and increased interlayer spacing. However, synchronously optimizing these two structures is challenging due to their inherent trade‐off. Herein, a tandem catalytic carbonization strategy is developed to construct HC with long graphite domains (La = 5.31 nm) and large interlayer spacing (d002 = 0.389 nm) simultaneously. Comprehensive in situ and ex situ tests unravel the catalytic selective bond breaking and aromatization effects of ZnCl2, the catalytic graphitic layers enlargement and occupied effects of formed ZnO and Zn in different temperature stages, leading to the formation of the unique structure. The optimal HCZ‐0.1 exhibits a high reversible capacity of 346.9 mAh g⁻¹ with a plateau capacity of 249.4 mAh g⁻¹, and high‐rate performance (114.0 mAh g⁻¹ at 5 A g⁻¹). In addition, the sodium storage mechanism and origin of enhanced Na⁺ kinetics of HCZ‐0.1 are also revealed. This work offers a precise method to engineer the graphite microcrystal structure in HC for superior sodium storage in the plateau region.
Article
Full-text available
The closed‐pore structure of hard carbons holds the key to high plateau capacity and rapid diffusion kinetics when applied as sodium‐ion battery (SIB) anodes. However, understanding and establishing the structure‐electrochemistry relationship still remains a significant challenge. This work, for the first time, introduces an innovative deep eutectic solvent (DES) cell‐shearing strategy to precisely tailor the cell structure of natural bamboo and consequently the closed‐pore in its derived hard carbons. The DES shearing force effectively modifies the pore architecture by simultaneously shearing and dissolving amorphous components to form closed pore cores with adjustable sizes, as well as disintegrating crystalline cellulose through generation of competing hydrogen bonds to elaborately tune the pore wall thickness and ordering. The optimized closed‐pore structure featuring appropriate pore size (∼2 nm) and ultra‐thin (1–3 layers) disordered pore walls, exhibits abundant active sites and delivers rapid ion diffusion kinetics and high reaction reversibility. Consequently, a high reversible capacity of 422 mAh g⁻¹ at 30 mA g⁻¹ along with an exceptional rate capability (318.6 mAh g⁻¹ at 6 A g⁻¹) are achieved, outperforming almost all previous reported hard carbons. The new concept of cell‐shearing chemistry for closed‐pore regeneration significantly advances the applications of biomass materials for energy storage.
Article
Full-text available
Room‐temperature sodium–sulfur (RT Na–S) batteries have become the most potential large‐scale energy storage systems due to the high theoretical energy density and low cost. However, the severe shuttle effect and the sluggish redox kinetics arising from the sulfur cathode cause enormous challenges for the development of RT Na–S batteries. This review systematically sheds light on the rational design strategies of integrating porous carbon matrix with “adsorption–catalysis” agents, including transition‐metal single‐atom, transition‐metal nanoclusters, transition‐metal compounds, or heterostructures. Moreover, the multistep reaction mechanism accompanied with the evolution process of various sodium polysulfides during the redox process is systematically summarized on the basis of electrochemical technique analysis and ex situ/in situ characterization. Finally, the future perspectives and potential research directions are outlined to provide a guideline for the continuous development of RT Na–S batteries. This review sheds light on the rational design strategies of integrating porous carbon matrix with “adsorption–catalysis” agents for room‐temperature sodium‐sulfur batteries (RT Na–S). The multi‐step reaction mechanism during the redox process is systematically summarized. Future perspectives and research directions are outlined to provide a guideline for the development of RT Na–S batteries.
Article
Full-text available
The sodium storage performance of a hard carbon (HC) anode in ether electrolytes exhibits a higher initial Coulombic efficiency (ICE) and better rate performance compared to conventional ester electrolytes. However, the mechanism behind faster Na storage kinetics for HC in ether electrolytes remains unclear. Herein, a unique solvated Na+ and Na+ co‐intercalation mechanism in ether electrolytes is reported using designed monodispersed HC nanospheres. In addition, a thin solid electrolyte interphase film with a high inorganic proportion formed in an ether electrolyte is visualized by cryo transmission electron microscopy and depth‐profiling X‐ray photoelectron spectroscopy, which facilitates Na+ transportation, and results in a high ICE. Furthermore, the fast solvated Na+ diffusion kinetics in ether electrolytes are also revealed via molecular dynamics simulation. Owing to the contribution of the ether electrolytes, an excellent rate performance (214 mAh g−1 at 10 A g−1 with an ultrahigh plateau capacity of 120 mAh g−1) and a high ICE (84.93% at 1 A g−1) are observed in a half cell; in a full cell, an attractive specific capacity of 110.3 mAh g−1 is achieved after 1000 cycles at 1 A g−1. A monodispersed nanospherules hard carbon anode is successfully synthesized, showing excellent electrochemical performances when matched with an ether‐based electrolyte in sodium‐ion batteries. The unique solvated Na+ and Na+ co‐intercalation mechanism and the formed thin solid electrolyte interphase film with low interface impedance in ether‐based electrolytes can significantly accelerate Na storage kinetics for hard carbon anodes.
Article
Full-text available
Heterostructures exhibit intriguing and significant properties for functional material applications, such as photosensing devices, semiconductor materials, and supercapacitors. Rechargeable batteries as typical energy‐storage devices have drawn widespread attention in the past several decades, on account of high energy density, being low‐cost, and ecofriendly. Preparing superior active materials is the critical technology to ameliorate the electrochemical performance of batteries. In recent years, the concept of constructing heterostructures for the application of electrode materials has been considered as a promising design approach. Among all the electrode materials, metal chalcogenides (MCs) have presented excellent properties due to their high theoretical capacity based on multielectron reaction. Herein, the progress on MCs with heterostructures is summarized in terms of various material species and their specific application for several typical battery systems. Finally, possible challenges and comprehensive perspectives are given to provide an instructive direction for the thoughtful design strategies of heterostructures and the development of MCs for next‐generations rechargeable batteries. Constructing heterostructures for advanced electrode materials have been considered as a potential design strategy. Metal chalcogenides (MCs) have presented excellent electrochemical performances due to their high theoretical capacity based on multielectron reaction. Herein, the progress on MCs with heterostructures is summarized in terms of various material species and their specific application for several typical battery systems.
Article
Full-text available
Development of high-energy-density anode is crucial for practical application of Na-ion battery as a post Li-ion battery. Hard carbon (HC), though a promising anode candidate, still has bottlenecks of insufficient capacity and unclear microscopic picture. Usage of the micropore has been recently discussed, however, the underlying sodiation mechanism is still controversial. Herein we examined the origin for the high-capacity sodiation of HC, based on density functional theory calculations. We demonstrated that nanometer-size Na cluster with 3–6 layers is energetically stable between two sheets of graphene, a model micropore, in addition to the adsorption and intercalation mechanisms. The finding well explains the extended capacity over typical 300 mAhg ⁻¹ , up to 478 mAhg ⁻¹ recently found in the MgO-templated HC. We also clarified that the MgO-template can produce suitable nanometer-size micropores with slightly defective graphitic domains in HC. The present study considerably promotes the atomistic theory of sodiation mechanism and complicated HC science.
Article
Full-text available
Highlights Hard-carbon anode dominated with ultra-micropores (< 0.5 nm) was synthesized for sodium-ion batteries via a molten diffusion–carbonization method. The ultra-micropores dominated carbon anode displays an enhanced capacity, which originates from the extra sodium-ion storage sites of the designed ultra-micropores. The thick electrode (~ 19 mg cm ⁻² ) with a high areal capacity of 6.14 mAh cm ⁻² displays an ultrahigh cycling stability and an outstanding low-temperature performance. Abstract Pore structure of hard carbon has a fundamental influence on the electrochemical properties in sodium-ion batteries (SIBs). Ultra-micropores (< 0.5 nm) of hard carbon can function as ionic sieves to reduce the diffusion of slovated Na ⁺ but allow the entrance of naked Na ⁺ into the pores, which can reduce the interficial contact between the electrolyte and the inner pores without sacrificing the fast diffusion kinetics. Herein, a molten diffusion–carbonization method is proposed to transform the micropores (> 1 nm) inside carbon into ultra-micropores (< 0.5 nm). Consequently, the designed carbon anode displays an enhanced capacity of 346 mAh g ⁻¹ at 30 mA g ⁻¹ with a high ICE value of ~ 80.6% and most of the capacity (~ 90%) is below 1 V. Moreover, the high-loading electrode (~ 19 mg cm ⁻² ) exhibits a good temperature endurance with a high areal capacity of 6.14 mAh cm ⁻² at 25 °C and 5.32 mAh cm ⁻² at − 20 °C. Based on the in situ X-ray diffraction and ex situ solid-state nuclear magnetic resonance results, the designed ultra-micropores provide the extra Na ⁺ storage sites, which mainly contributes to the enhanced capacity. This proposed strategy shows a good potential for the development of high-performance SIBs.
Article
Full-text available
Sodium is abundant on earth and has similar chemical properties to lithium, thus sodium‐ion batteries (SIBs) have been considered as one of the most promising alternative energy storage systems to lithium‐ion batteries (LIBs). Meanwhile, a new energy storage device called sodium dual‐ion batteries (SDIBs) is attracting much attention due to its high voltage platform, low production cost, and environmental benignity coming from the feature of directly using graphite as the cathode. However, due to the large mass and ionic radius of sodium atoms, SIBs and SDIBs exhibit low energy density and inferior cycling life than LIBs. Over the last few years, tremendous efforts, especially in the area of anode materials, have been made to improve the electrochemical performance of SIBs and SDIBs. Reviewing and summarizing the previous studies will be helpful for future exploration and optimization. Here, we summarized the recent progress on anode materials for both SIBs and SDIBs according to the reaction mechanism. The structural design, reaction mechanism, and electrochemical performance of the anode materials are briefly discussed. In addition, we also propose the fundamental challenges, potential solutions, and perspectives in this field. It is hoped that this review may advance the development of anode materials for sodium storage. This article is protected by copyright. All rights reserved.
Article
Full-text available
Hard carbon is the material of choice for sodium ion battery anodes. Capacities comparable to those of lithium/graphite can be reached, but the understanding of the underlying sodium storage mechanisms remains fragmentary. A two‐step process is commonly observed, where sodium first adsorbs to polar sites of the carbon (“sloping region”) and subsequently fills small voids in the material (“plateau region”). To study the impact of nitrogen functionalities and pore geometry on sodium storage, a systematic series of nitrogen‐doped hard carbons is synthesized. The nitrogen content is found to contribute to sloping capacity by binding sodium ions at edges and defects, whereas higher plateau capacities are found for materials with less nitrogen content and more extensive graphene layers, suggesting the formation of 2D sodium structures stabilized by graphene‐like pore walls. In fact, up to 84% of the plateau capacity is measured at potentials less than 0 V versus metallic Na, that is, quasimetallic sodium can be stabilized in such structure motifs. Finally, gas physisorption measurements are related to charge–discharge data to identify the energy storage relevant pore architectures. Interestingly, these are pores inaccessible to probe gases and electrolytes, suggesting a new view on such “closed pores” required for efficient sodium storage.
Article
Full-text available
Hard carbon (HC) is the most promising anode material for sodium‐ion batteries (SIBs), nevertheless, the understanding of sodium storage mechanism in HC is very limited. As an important aspect of storage mechanism, the steady state of sodium stored in HC has not been revealed clearly to date. Herein, the formation mechanism of quasi‐metallic sodium and the quasi‐ionic bond between sodium and carbon within the electrochemical reaction on the basis of theoretical calculations are disclosed. The presence of quasi‐metallic sodium is further confirmed with the assistance of a specific reaction between the sodiated HC electrode and ethanol, by analyzing the reaction products with Fourier‐transform infrared spectroscopy, gas chromatography, and nuclear magnetic resonance. Moreover, based on the specific chemical reaction, the composition of fully sodiated HC is estimated to be NaC6.7, and the corresponding capacity of sucrose‐derived HC is calculated to be 333.4 mAh g⁻¹ in SIBs, matching well with the experimental result. This work helps to reveal the steady state of sodium and improve the understanding of sodium storage behavior in HC from the aspect of charge transfer. In addition, the proposed method is also expected to pave the way to investigate sodium storage mechanisms in other electrode systems.
Article
Full-text available
The pursuit of energy density has driven electric vehicle (EV) batteries from using lithium iron phosphate (LFP) cathodes in early days to ternary layered oxides increasingly rich in nickel; however, it is impossible to forgo the LFP battery due to its unsurpassed safety, as well as its low cost and cobalt-free nature. Here we demonstrate a thermally modulated LFP battery to offer an adequate cruise range per charge that is extendable by 10 min recharge in all climates, essentially guaranteeing EVs that are free of range anxiety. Such a thermally modulated LFP battery designed to operate at a working temperature around 60 °C in any ambient condition promises to be a well-rounded powertrain for mass-market EVs. Furthermore, we reveal that the limited working time at the high temperature presents an opportunity to use graphite of low surface areas, thereby prospectively prolonging the EV lifespan to greater than two million miles.
Article
Various properties of sodium ion batteries deteriorate severely when dropping to subzero temperature. Herein, we reveal an accelerated charge-transfer mechanism for high-voltage Na3V2(PO4)2F3 cathode through constructing weakly-solvating architecture, which endows it with superior temperature adaptability (capacity retention of C−25∘C/C25∘C reaches 90.8%). The resulting weak solvation effects synergistically lower the activation energy barrier for charge-transfer reactions, thus accelerating the kinetics at low temperature and increasing the energy density by ∼75 Wh Kg⁻¹. Ab initio molecular dynamics calculations show that a weakly-solvating structure forms spontaneously in a low-concentration electrolyte (merely 0.3M) and thereby facilitates Na⁺ desolvation process. Besides, visual TOF-SIMS confirms the construction of a dense and uniform cathode/electrolyte interface layer, which optimizes the interface chemistry and improves the interfacial kinetics. In-situ and ex-situ XRD also evidence a smaller degree of structural evolution of the Na3V2(PO4)2F3 cathode, which contributes to long-term durability (attaining a high capacity retention of 93.4% after 1000 cycles at −25°C). Furthermore, it is demonstrated that under such extreme conditions the Na3V2(PO4)2F3||hard-carbon full cell functions well for over 300 hours. These findings elucidate the roles of weak solvation construction in realizing faster kinetics for high-voltage cathodes and provide a feasible pathway for achieving more practical sodium ion batteries.