Limits...
A 3.8-V earth-abundant sodium battery electrode.

Barpanda P, Oyama G, Nishimura S, Chung SC, Yamada A - Nat Commun (2014)

Bottom Line: Rechargeable lithium batteries have ushered the wireless revolution over last two decades and are now matured to enable green automobiles.However, their performance is limited owing to low operating voltage and sluggish kinetics.Here we report a hitherto-unknown material with entirely new composition and structure with the first alluaudite-type sulphate framework, Na2Fe2(SO4)3, registering the highest-ever Fe(3+)/Fe(2+) redox potential at 3.8 V (versus Na, and hence 4.1 V versus Li) along with fast rate kinetics.

View Article: PubMed Central - PubMed

Affiliation: 1] Department of Chemical System Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan [2] Unit of Element Strategy Initiative for Catalysts and Batteries, ESICB, Kyoto University, Kyoto 615-8510, Japan [3] Materials Research Center, Indian Institute of Science, Bangalore 560012, India [4].

ABSTRACT
Rechargeable lithium batteries have ushered the wireless revolution over last two decades and are now matured to enable green automobiles. However, the growing concern on scarcity and large-scale applications of lithium resources have steered effort to realize sustainable sodium-ion batteries, Na and Fe being abundant and low-cost charge carrier and redox centre, respectively. However, their performance is limited owing to low operating voltage and sluggish kinetics. Here we report a hitherto-unknown material with entirely new composition and structure with the first alluaudite-type sulphate framework, Na2Fe2(SO4)3, registering the highest-ever Fe(3+)/Fe(2+) redox potential at 3.8 V (versus Na, and hence 4.1 V versus Li) along with fast rate kinetics. Rare-metal-free Na-ion rechargeable battery system compatible with the present Li-ion battery is now in realistic scope without sacrificing high energy density and high power, and paves way for discovery of new earth-abundant sustainable cathodes for large-scale batteries.

No MeSH data available.


Related in: MedlinePlus

Overall comparison of the Fe-based cathode materials that can function as Na sources in Na-ion battery system.Polyanionic cathode materials are shown as green boxes and simple oxides/fluorides as blue, respectively. Horizontal bars represent average voltage. Yellow band indicates voltage region that can ensure the compatibility with Li-ion batteries. The new compound Na2Fe2(SO4)3 is presented by the red box together with its expected dashed-red region based on the theoretical capacity. (*The capacity and voltage of P2-Na2/3−x[Fe1/2Mn1/2]O2 is assumed by 0<x<2/3 region by inherent amount of Na with large hysteresis including both Fe4+/Fe3+ and Mn4+/Mn3+ redox reactions, as separately denoted with dashed pale blue box. Dashed pale green box for NaFePO4 indicate it cannot be directly synthesized and sluggish kinetics in electrode reaction.)
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4109020&req=5

f5: Overall comparison of the Fe-based cathode materials that can function as Na sources in Na-ion battery system.Polyanionic cathode materials are shown as green boxes and simple oxides/fluorides as blue, respectively. Horizontal bars represent average voltage. Yellow band indicates voltage region that can ensure the compatibility with Li-ion batteries. The new compound Na2Fe2(SO4)3 is presented by the red box together with its expected dashed-red region based on the theoretical capacity. (*The capacity and voltage of P2-Na2/3−x[Fe1/2Mn1/2]O2 is assumed by 0<x<2/3 region by inherent amount of Na with large hysteresis including both Fe4+/Fe3+ and Mn4+/Mn3+ redox reactions, as separately denoted with dashed pale blue box. Dashed pale green box for NaFePO4 indicate it cannot be directly synthesized and sluggish kinetics in electrode reaction.)

Mentions: Searching for novel low-cost cathode materials for rechargeable Na-ion batteries, we have synthesized a whole new family of cathode materials with general formula Na2M2(SO4)3. The first such candidate, Fe-based Na2Fe2(SO4)3, delivers a reversible capacity exceeding 100 mAh g−1 with the working Fe3+/Fe2+ potential located at 3.8 V (versus Na/Na+), the highest known value among all Fe-based insertion compounds. This abnormally high voltage is compatible with the thermodynamic limit of current generation organic electrolytes offering stable/safe operation. In addition, it offers excellent rate kinetics and cycling stability without demanding any additional cathode optimization. It forms an open framework host for efficient (de)intercalation of Na ions with very low activation energy. Operating voltage and reversible capacity of various known iron-based cathode for Na-‘ion’ (cathode functions as whole Na source) battery system are summarized in Fig. 5. The new material Na2Fe2(SO4)3 is benchmarking and worth further optimizing as it is the first Fe-based cathode for Na battery to offer high voltage compatible with Li battery system. Moreover, further effort to reach theoretical capacity by full utilization of inherent Na ions (85% in the present paper) can lead to energy density of >540 Wh kg−1, which is higher than those of LiMn2O4 (430 Wh kg−1) and LiFePO4 (500 Wh kg−1).


A 3.8-V earth-abundant sodium battery electrode.

Barpanda P, Oyama G, Nishimura S, Chung SC, Yamada A - Nat Commun (2014)

Overall comparison of the Fe-based cathode materials that can function as Na sources in Na-ion battery system.Polyanionic cathode materials are shown as green boxes and simple oxides/fluorides as blue, respectively. Horizontal bars represent average voltage. Yellow band indicates voltage region that can ensure the compatibility with Li-ion batteries. The new compound Na2Fe2(SO4)3 is presented by the red box together with its expected dashed-red region based on the theoretical capacity. (*The capacity and voltage of P2-Na2/3−x[Fe1/2Mn1/2]O2 is assumed by 0<x<2/3 region by inherent amount of Na with large hysteresis including both Fe4+/Fe3+ and Mn4+/Mn3+ redox reactions, as separately denoted with dashed pale blue box. Dashed pale green box for NaFePO4 indicate it cannot be directly synthesized and sluggish kinetics in electrode reaction.)
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4109020&req=5

f5: Overall comparison of the Fe-based cathode materials that can function as Na sources in Na-ion battery system.Polyanionic cathode materials are shown as green boxes and simple oxides/fluorides as blue, respectively. Horizontal bars represent average voltage. Yellow band indicates voltage region that can ensure the compatibility with Li-ion batteries. The new compound Na2Fe2(SO4)3 is presented by the red box together with its expected dashed-red region based on the theoretical capacity. (*The capacity and voltage of P2-Na2/3−x[Fe1/2Mn1/2]O2 is assumed by 0<x<2/3 region by inherent amount of Na with large hysteresis including both Fe4+/Fe3+ and Mn4+/Mn3+ redox reactions, as separately denoted with dashed pale blue box. Dashed pale green box for NaFePO4 indicate it cannot be directly synthesized and sluggish kinetics in electrode reaction.)
Mentions: Searching for novel low-cost cathode materials for rechargeable Na-ion batteries, we have synthesized a whole new family of cathode materials with general formula Na2M2(SO4)3. The first such candidate, Fe-based Na2Fe2(SO4)3, delivers a reversible capacity exceeding 100 mAh g−1 with the working Fe3+/Fe2+ potential located at 3.8 V (versus Na/Na+), the highest known value among all Fe-based insertion compounds. This abnormally high voltage is compatible with the thermodynamic limit of current generation organic electrolytes offering stable/safe operation. In addition, it offers excellent rate kinetics and cycling stability without demanding any additional cathode optimization. It forms an open framework host for efficient (de)intercalation of Na ions with very low activation energy. Operating voltage and reversible capacity of various known iron-based cathode for Na-‘ion’ (cathode functions as whole Na source) battery system are summarized in Fig. 5. The new material Na2Fe2(SO4)3 is benchmarking and worth further optimizing as it is the first Fe-based cathode for Na battery to offer high voltage compatible with Li battery system. Moreover, further effort to reach theoretical capacity by full utilization of inherent Na ions (85% in the present paper) can lead to energy density of >540 Wh kg−1, which is higher than those of LiMn2O4 (430 Wh kg−1) and LiFePO4 (500 Wh kg−1).

Bottom Line: Rechargeable lithium batteries have ushered the wireless revolution over last two decades and are now matured to enable green automobiles.However, their performance is limited owing to low operating voltage and sluggish kinetics.Here we report a hitherto-unknown material with entirely new composition and structure with the first alluaudite-type sulphate framework, Na2Fe2(SO4)3, registering the highest-ever Fe(3+)/Fe(2+) redox potential at 3.8 V (versus Na, and hence 4.1 V versus Li) along with fast rate kinetics.

View Article: PubMed Central - PubMed

Affiliation: 1] Department of Chemical System Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan [2] Unit of Element Strategy Initiative for Catalysts and Batteries, ESICB, Kyoto University, Kyoto 615-8510, Japan [3] Materials Research Center, Indian Institute of Science, Bangalore 560012, India [4].

ABSTRACT
Rechargeable lithium batteries have ushered the wireless revolution over last two decades and are now matured to enable green automobiles. However, the growing concern on scarcity and large-scale applications of lithium resources have steered effort to realize sustainable sodium-ion batteries, Na and Fe being abundant and low-cost charge carrier and redox centre, respectively. However, their performance is limited owing to low operating voltage and sluggish kinetics. Here we report a hitherto-unknown material with entirely new composition and structure with the first alluaudite-type sulphate framework, Na2Fe2(SO4)3, registering the highest-ever Fe(3+)/Fe(2+) redox potential at 3.8 V (versus Na, and hence 4.1 V versus Li) along with fast rate kinetics. Rare-metal-free Na-ion rechargeable battery system compatible with the present Li-ion battery is now in realistic scope without sacrificing high energy density and high power, and paves way for discovery of new earth-abundant sustainable cathodes for large-scale batteries.

No MeSH data available.


Related in: MedlinePlus