CHEMISTRY-A EUROPEAN JOURNAL
·
2020
·Vol. 26
·期 45
·10314-10320
·
IF 4.857
Guiqiang Cao,Zhikang Wang,Da Bi,Jing Zheng,Qingxue Lai,Yanyu Liang
Graphical Atomic cat : A single-atom Fe@NG electrocatalyst serves as the coating of separators for high-performance Li-S batteries. Atomically dispersed Fe sites on the graphene framework promote the conversion efficiency of LiPS. The Fe@NG electrocatalyst delivers an initial capacity of 1616 mA h g −1 at 0.1 C, and a reversible capacity of 546 mA h g −1 after 200 cycles at 2 C (70 % capacity retention). Lithium-sulfur batteries have been considered as potential electrochemical energy-storage devices owing to their satisfactory theoretical energy density. Nonetheless, the inferior conversion efficiency of polysulfides in essence leads to fast capacity decay during the discharge/charge cycle. In this work, it is successfully demonstrated that the conversion efficiency of lithium polysulfides is remarkably enhanced by employing a well-distributed atomic-scale Fe-based catalyst immobilized on nitrogen-doped graphene (Fe@NG) as a coating of separator in lithium-sulfur batteries. The quantitative electrocatalytic efficiency of the conversion of lithium polysulfides is determined through cyclic voltammetry. It is also proven that the Fe-N X configuration with highly catalytic activity is quite beneficial for the conversion of lithium polysulfides. In addition, the adsorption and permeation experiments distinctly indicate that the strong anchoring effect, originated from the charge redistribution of N doping into the graphene matrix, inhibits the movement of lithium polysulfides. Thanks to these advantages, if the as-prepared Fe@NG catalyst is combined with polypropylene and applied as a separator (Fe@NG/PP) in Li-S batteries, a high initial capacity (1616 mA h g −1 at 0.1 C), excellent capacity retention (93 % at 0.2 C, 70 % at 2 C), and superb rate performance (820 mA h g −1 at 2 C) are achieved.
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DOI
PubMed
高影响因子
ACS Nano
·
2025
·
IF 16
Runyuan Cao,Zichun Zhou,Xianhui Nie,Yongfeng Li,Chuanzhong Lai,Keyi Chen,Chilin Li
Conventional intercalation-type cathodes for lithium batteries are plagued by rapid capacity decay and unsatisfactory cycling lifespans when operating at subzero temperatures. Conversion-type iron fluoride seems to compensate for these setbacks due to its dramatic theoretical capacity via a three-electron transfer mechanism, but suffers from an irreversible solid–solid phase transition with the collapse of the charge-transporting tunnel and insulating LiF precipitation over the cathode–electrolyte interphase (CEI) layer. Herein, we propose a metal–organic framework in situ etching-fluorination strategy to construct a porous micron-brick monolithic grain cathode with rich heterojunctions of hexagonal tungsten bronze (HTB) FeF3 and rutile FeF2 with an epitaxial intergrowth mode. Owing to the optimized configuration with a self-healing built-in interfacial electric field, open diffusional channels, as well as topotactic conversion and catalyzing functions of FeF2 on Li–F splitting, this heterostructure fluoride enables a high energy density (1114 Wh kg–1 at 215 W kg–1) and high-rate performance (337 mAh g–1 at 1000 mA g–1) at room temperature. These effects also endow the cathode with outstanding low-temperature performance with an average capacity of 170 mAh g–1 for 100 cycles and a discharge capacity of 50 mAh under a 6-layer pouch cell configuration at −20 °C.
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DOI
PubMed
高影响因子
Journal of Energy Chemistry
·
2025
·
IF 14.9
Zichen Zhang,Jingyi Liu,Nan Chen,Tao Jiang,Shiyu Yao,Gang Chen,Deping Wang,Fei Du
Li-rich Mn-based oxides (LRMO) are of great significance in achieving high energy density all-solid-state lithium batteries (ASSLBs), owing to their high theoretical capacity and high operation voltage. Unfortunately, their practical application is hindered by severe interface degradation due to the chemical oxidation and electrochemical decomposition of solid electrolytes (SEs), driven by high-active oxygen and electron sources from LRMO. Herein, an interfacial modification strategy is proposed to stabilize the surface lattice oxygen of LRMO and reduce electronic conduction between LRMO and SEs, synergistically. Accordingly, the byproducts from chemical oxidation (InO − ) and electrochemical decomposition (LiCl − ) are largely suppressed, leading to superior interfacial transport with the lowest resistance. Consequently, the ASSLB achieves a high reversible capacity of 227.9 mA h g −1 at 0.1 C, a cycling stability of 90.1% capacity retention after 200 cycles at 0.1 C, and a superior rate capability with a capacity of 81.7 mA h g −1 at 3.0 C. This study enriches the fundamental understanding of LRMO/SEs interfacial evolution during the electrochemical cycling and the proposed interfacial modification strategy benefits the future design of Li-rich compounds for ASSLBs.
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DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2025
·
IF 4.3
Shuang Sun,Yuefeng Deng,Ji Chen,Rui Qin,Zhongte Du,Qianshun Wen,Yang Meng
With the amid surging demand for lithium, solvent extraction has gradually developed into a key method for lithium recovery in industry. Due to the problems of large dissolution loss and high extraction equilibrium pH of β -diketone system, di-(2-ethylhexyl) phosphinic acid (P227) was selected to recover Li + from the desorption solution of salt lakes (SL-DS). Compared with di-2-ethylhexyl phosphoric acid (P204), 2-ethylhexyl phosphoric acid mono 2-ethylhexyl ester (P507), and bis (2,4,4-trimethylpentyl) phosphinic acid (Cyanex272), P227 showed better separation ability for Li + and Na + . The extraction conditions, including saponification degree, initial pH, extractant concentration and phase ratio were studied. It could be found that the extraction efficiency of Li + was maintained at a high level in the initial pH range of 2.25–12.61. A cascade process consisting of eight-stage extraction and five-stage scrubbing was performed to verify the feasibility of this technology. 99.9 % of Li + from the SL-DS was extracted at the equilibrium pH of 7.60, and P227 exhibited superior selectivity for Li + over Na + . Moreover, under the optimal condition of 3.8 mol/L HCl and O/A of 20:1, the stripping ratio of Li + reached 99.76 % via a four-stage stripping experiment. The Li + concentration of stripping liquor attained 23.11 g/L and a high-purity (99.5 %) Li 2 CO 3 product was obtained by precipitation. After five cycles, P227 demonstrated excellent regeneration stability. Eventually, the composition of extraction complex was revealed as LiR•NaR by slope analysis, and the cation exchange mechanism was further confirmed using FT-IR and 31 P NMR.
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高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2016
·Vol. 27
·期 3
·1605011
·
IF 11.382
Yaxiong Yang,Yongfeng Liu,Kaichao Pu,Xing Chen,He Tian,Mingxia Gao,Min Zhu,Hongge Pan
In this study, an amorphous Li 2 CO 3 -coated nanocrystalline α-Fe 2 O 3 hierarchical structure is synthesized for the first time using a facile one-step mechanochemical process at room temperature, taking advantage of the concurrence of repeated fracture-cold welding of material's particles and a gas-solid redox reaction. The conformal coating and hierarchical structure significantly increase the cycling durability and rate capability. Typically, a 1–3 nm thick amorphous Li 2 CO 3 layer is conformally coated on Fe 2 O 3 nanocrystallines (≈10 nm in size) that form hierarchically aggregated particles 400–800 nm in size by ball milling α-Fe 2 O 3 with LiH in CO 2 . The prepared Li 2 CO 3 -coated nanocrystalline α-Fe 2 O 3 exhibits highly stable long-term cyclability as it delivers a reversible capacity of 975 mAh g −1 with 99% of retention after 400 cycles at 100 mA g −1 . At a high rate of 3000 mA g −1 , its reversible capacity still remains at 537 mAh g −1 , superior to the uncoated counterpart (311 mAh g −1 ). Moreover, amorphous Li 2 O and Li 2 CO 3 coatings are also similarly produced on Fe 2 O 3 and NiO nanocrystallines, respectively, representing the general applicability of this mechanochemical approach.
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高影响因子
Small
·
2018
·Vol. 14
·期 41
·1802443
·
IF 9.598
Xiao-Tian Gao,Ying Xie,Xiao-Dong Zhu,Ke-Ning Sun,Xu-Ming Xie,Yi-Tao Liu,Jian-Yong Yu,Bin Ding
Being conductive and flexible, 2D transition metal nitrides and carbides (MXenes) can serve in Li–S batteries as sulfur hosts to increase the conductivity and alleviate the volume expansion. However, the surface functional groups, such as OH and F, weaken the ability of bare MXenes in the chemisorption of polysulfides. Besides, they create numerous hydrogen bonds which make MXenes liable to restack, resulting in substantial loss of active area and, thus, inaccessibility of ions and electrolyte. Herein, a facile, one-step strategy is developed for the growth of TiO 2 quantum dots (QDs) on ultrathin MXene (Ti 3 C 2 T x ) nanosheets by cetyltrimethylammonium bromide-assisted solvothermal synthesis. These QDs act as spacers to isolate the MXene nanosheets from restacking, and preserve their 2D geometry which guarantees larger electrode–electrolyte contact area and higher sulfur loading. The stronger adsorption energy of polysulfides with TiO 2 (than with Ti 3 C 2 T x ), as proven by density functional theory calculations, is essential for better on-site polysulfide retention. The ultrathin nature and protected conductivity ensure rapid ion and electron diffusion, and the excellent flexibility maintains high mechanical integrity. In result, the TiO 2 QDs@MXene/S cathode exhibits significantly improved long-term cyclability and rate capability, disclosing a new opportunity toward fast and stable Li–S batteries.
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高影响因子
Journal of Physical Chemistry C
·
2021
·
IF 4.126
Di Wu,Wen Ren,Yang Yang,Jiulin Wang,Yanna NuLi
A magnesium–sulfur (Mg–S) battery system is considered a high-performance candidate for next-generation secondary batteries, because of its prominent advantages such as high safety, low cost, and high energy density. However, the shuttle effect caused by the dissolution of polysulfides leads to irreversible loss of capacity. Herein, we prepare a S0.96Se0.04@CMK3 composite (with a high S + Se content of 82.6 wt %) and employ the composite material as a cathode for Mg batteries with easily prepared hybrid electrolytes. The electronic conductivity of the cathode material increases by 18 orders of magnitude after Se doping, from 5 × 10–28 to 6.5 × 10–10 S m–1. Compared with S@CMK3, doped Se in S0.96Se0.04@CMK3 plays an important role in maintaining capacity stability by lowering polarization, facilitating electron transport, and improving reaction kinetics. The S0.96Se0.04@CMK3 cathode delivers a stable and reversible capacity of 492.9 mAh g–1 after 110 cycles, which is almost twice that of the S@CMK cathode without Se doping, and better rate performance. This Se-doping strategy proposes an effective method to exploit high-performance cathodes for Mg–S batteries.
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高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Zihao Su,Zhihao Guo,Haoyu Xie,Meizhen Qu,Gongchang Peng,Hao Wang
Li-rich Mn-based cathode materials (LLOs) are often faced with problems such as low initial Coulombic efficiency (ICE), limited rate performance, voltage decay, and structural instability. Addressing these problems with a single approach is challenging. To overcome these limitations, we developed an LLO with surface functionalization using a simple fabrication method. This two-step process involved a liquid-stage NaBF4 treatment followed by an in situ chemical reaction during sintering. This reaction led to the creation of oxygen vacancies (OV), spinel structures, and doping with Na at the Li site, B at the tetrahedral interstitial spaces of O in both the transition-metal (TM) layer and Li layers as well as the octahedral interstices in the TM layer, and F at the O site. We have carried out a thorough study and employed density functional theory calculations to reveal the hidden mechanisms. The treatment not only increases the electrical conductivity but also changes the oxygen charge environment and inhibits lattice oxygen activity. Surprisingly, the B–O bond is so strong that it prevents the migration of TM within the tetrahedral interstitial spaces of O in both the TM and Li layers, hence stabilizing its structure. This bonding interaction strengthens the transition of the TM 3d and O 2p states to lower energy levels, thus causing an increase in the redox potentials. Hence, a rise in the operating voltage occurs. Of special importance, this therapy dramatically increases the ICE to 90.29% and keeps a specified capacity of 203.3 mAh/g after 100 cycles at 1C, which is an excellent capacity retention of 89.94%. This study introduces ideas and methods to tackle the challenges associated with LLOs in batteries. It also provides compelling evidence for the development of high-energy-density Li-ion batteries.
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高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Pengzu Kou,Zhigui Zhang,Zhaoyang Dong,Runguo Zheng,Zhishuang Song,Zhiyuan Wang,Hongyu Sun,Yanguo Liu
Lithium-rich manganese-based cathode (LRM) is considered to be the most promising cathode materials for next-generation lithium-ion batteries due to its high energy density. However, the low initial coulombic efficiency and poor rate performance are severe problems in the commercialization of LRM. Herein, we use an ascorbic acid (VC) modulation strategy to create spinel-carbon composite coatings and dual defects (oxygen vacancies, stack faults) on the surface of LRM. The composite surface coating and defects play a synergistic role in inhibiting interfacial side reactions, enhancing structural stability, and improving electrical conductivity as well as lithium-ion diffusion kinetics. As a result, the modified LRMs exhibit a specific capacity of 251.7mAh/g with an improved initial coulombic efficiency (ICE) of 82.3 % (pristine 72.9 %), enhanced rate capability (135 mAh/g at 5C), and long-term cyclability of 90 % retention after 200 cycles compared with the pristine (78 % retention after 200 cycles). The performance improvement of the modified LRMs is attributable to the composite coating and the dual defects, which ensure the LRM with a more stable structure (smaller volume change of 2.4 % compared with the original sample of 3.65 %). This strategy provides an efficient and environmentally friendly idea of surface modification for boosting the electrochemical performance.
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高影响因子
DALTON TRANSACTIONS
·
2012
·Vol. 41
·期 29
·8822-8828
·
IF 3.838
Dezhi Chen,Wei Wei,Ruining Wang,Xiu-feng Lang,Yu Tian,Lin Guo
Olivine-structured LiMnPO4 with 3D foldaway-lantern-like hierarchical structures have been prepared via a one-step, template-free, solvothermal approach in ethylene glycol. The foldaway-lantern-like LiMnPO4 microstructures are composed of numerous nanoplates with thickness of about 20 nm. A series of electron microscopy characterization results indicate that the obtained primary LiMnPO4 nanoplates are single crystalline in nature, growing along the [010] direction in the (100) plane. Time-dependent morphology evolution suggests that ethylene glycol plays dual roles in oriented growth and self-assembly of such unique structures. After carbon coating, the as-prepared LiMnPO4 cathode demonstrated a flat potential at 4.1 V versus Li/Li+ with a specific capacity close to 130 mA h g−1 at 0.1 C, along with excellent cycling stability.
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Chia-Tse Lee,Haoyuan Zheng,Chen Jin,Hang Che,Li Wang,Yuyuan Zhao,Shixuan He,Xinhua Wang,Yifeng Yu,Mi Yan
Metal nitrogen hydride (Li-Mg-N-H) is regarded as an ideal hydrogen storage material for automotive applications due to its advantages of high hydrogen storage capacity (5.6 wt%), low operating temperature, and good cycling performance, but the comprehensive hydrogen storage performance of this material still could be improved. For this reason, this paper constructed a Li-Na-Mg-N-H composite system by synthesizing NaMgH 3 to replace MgH 2 in the Li-Mg-N-H system. The improvement of the hydrogen absorption and desorption properties of the composite system after the replacement of MgH 2 by NaMgH 3 was investigated. Various properties and test results showed that the composite system after the replacement of MgH 2 by NaMgH 3 showed better hydrogen absorption and desorption properties. The initial/peak hydrogen release temperatures of Li-Na-Mg-N-H decreased from 135 ˚C/245 ˚C to 105 ˚C/145 ˚C, and the apparent activation energy of hydrogen release was reduced from 114.90 to 104.05 kJ/mol which means the kinetics of hydrogen absorption and desorption was greatly improved. The mechanism study shows that NaMgH 3 will react with LiNH 2 and forms the intermediate product Li 3 Na(NH 2 ) 4 during the hydrogen release process, which changes the hydrogen desorption pathway of the composite system and thus the hydrogen absorption and desorption kinetics were improved.
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高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Zhigui Zhang,Pengzu Kou,Yu Chen,Runguo Zheng,Zhiyuan Wang,Hongyu Sun,Yanguo Liu,Dan Wang
Li-rich manganese-based oxide (LRMO) is considered one of the most promising cathode materials for next-generation lithium-ion batteries due to its high energy density. However, many issues need to be addressed before its large-scale commercialization, including significant voltage decay and capacity fading. Herein, a Sn 4+ /Na + co-doping induced integrated defect structure (oxygen vacancies, stacking faults, and surface spinel phase) strategy is proposed to suppress the voltage decay and enhance the cycling performance of LRMO. The integrated surface defect structures have significantly favorable effects on the LRMO, where the oxygen vacancies remove surface labile oxygen and suppress surface oxygen release, the induced stacking faults alleviate the stress accumulation during cycling, the surface spinel phase promotes the Li + diffusion and prevents the outward migration of cations, and the co-doped Sn 4+ /Na + stabilize the layered structure. As a result, the modified sample Na 2 SnO 3 -1 % (NSO-1) achieves excellent cycling performance (capacity of 207 mAh/g and capacity retention of 96.71 % after 100 cycles at 0.5C) and a smaller voltage decay (less than 1.5 mV per cycle) compared with the unmodified LRMO. This work provides a new valuable strategy to suppress capacity fading and voltage decay of LRMO through dual-element substitution induced surface defect engineering.
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高影响因子
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