Author
Dong-Hwa Seo
Other affiliations: University of California, Berkeley, KAIST, University of California ...read more
Bio: Dong-Hwa Seo is an academic researcher from Ulsan National Institute of Science and Technology. The author has contributed to research in topics: Lithium & Cathode. The author has an hindex of 47, co-authored 92 publications receiving 11818 citations. Previous affiliations of Dong-Hwa Seo include University of California, Berkeley & KAIST.
Papers
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TL;DR: In this paper, both negative and positive electrode materials in NIB are briefly reviewed, and it is concluded that cost-effective NIB can partially replace Li-ion batteries, but requires further investigation and improvement.
Abstract: Lithium (Li)-ion batteries (LIB) have governed the current worldwide rechargeable battery market due to their outstanding energy and power capability. In particular, the LIB's role in enabling electric vehicles (EVs) has been highlighted to replace the current oil-driven vehicles in order to reduce the usage of oil resources and generation of CO2 gases. Unlike Li, sodium is one of the more abundant elements on Earth and exhibits similar chemical properties to Li, indicating that Na chemistry could be applied to a similar battery system. In the 1970s-80s, both Na-ion and Li-ion electrodes were investigated, but the higher energy density of Li-ion cells made them more applicable to small, portable electronic devices, and research efforts for rechargeable batteries have been mainly concentrated on LIB since then. Recently, research interest in Na-ion batteries (NIB) has been resurrected, driven by new applications with requirements different from those in portable electronics, and to address the concern on Li abundance. In this article, both negative and positive electrode materials in NIB are briefly reviewed. While the voltage is generally lower and the volume change upon Na removal or insertion is larger for Na-intercalation electrodes, compared to their Li equivalents, the power capability can vary depending on the crystal structures. It is concluded that cost-effective NIB can partially replace LIB, but requires further investigation and improvement.
2,885 citations
TL;DR: It is demonstrated how very specific local Li-excess environments around oxygen atoms necessarily lead to labile oxygen electrons that can be more easily extracted and participate in the practical capacity of cathodes.
Abstract: Lithium-ion batteries are now reaching the energy density limits set by their electrode materials, requiring new paradigms for Li(+) and electron hosting in solid-state electrodes. Reversible oxygen redox in the solid state in particular has the potential to enable high energy density as it can deliver excess capacity beyond the theoretical transition-metal redox-capacity at a high voltage. Nevertheless, the structural and chemical origin of the process is not understood, preventing the rational design of better cathode materials. Here, we demonstrate how very specific local Li-excess environments around oxygen atoms necessarily lead to labile oxygen electrons that can be more easily extracted and participate in the practical capacity of cathodes. The identification of the local structural components that create oxygen redox sets a new direction for the design of high-energy-density cathode materials.
950 citations
TL;DR: In this paper, the surface lattice structures of LiNi0.5Co0.2Mn0.3O2 were investigated under various cutoff voltage conditions, and it was shown that the pristine rhombohedral phase tends to transform into a mixture of spinel and rock salt phases.
Abstract: LiNixCoyMnzO2 (NCM, 0 ≤ x,y,z 4.3 V) required for high capacity is inevitably accompanied by a more rapid capacity fade over numerous cycles. Here, the degradation mechanisms of LiNi0.5Co0.2Mn0.3O2 are investigated during cycling under various cutoff voltage conditions. The surface lattice structures of LiNi0.5Co0.2Mn0.3O2 are observed to suffer from an irreversible transformation; the type of transformation depends on the cutoff voltage conditions. The surface of the pristine rhombohedral phase tends to transform into a mixture of spinel and rock salt phases. Moreover, the formation of the rock salt phase is more dominant under a higher voltage operation (≈4.8 V), which is attributable to the highly oxidative environment that triggers the oxygen loss from the surface of the material. The presence of the ionically insulating rock salt phase may result in sluggish kinetics, thus deteriorating the capacity retention. This implies that the prevention of surface structural degradation can provide the means to produce and retain high capacity, as well as stabilize the cycle life of LiNi0.5Co0.2Mn0.3O2 during high-voltage operations.
893 citations
TL;DR: A comprehensive review of ongoing materials research on nonaqueous K-ion batteries is provided in this paper, where the status of new materials discovery and insights to help understand the K-storage mechanisms are provided.
Abstract: Author(s): Kim, H; Kim, JC; Bianchini, M; Seo, DH; Rodriguez-Garcia, J; Ceder, G | Abstract: The development of rechargeable batteries using K ions as charge carriers has recently attracted considerable attention in the search for cost-effective and large-scale energy storage systems. In light of this trend, various materials for positive and negative electrodes are proposed and evaluated for application in K-ion batteries. Here, a comprehensive review of ongoing materials research on nonaqueous K-ion batteries is offered. Information on the status of new materials discovery and insights to help understand the K-storage mechanisms are provided. In addition, strategies to enhance the electrochemical properties of K-ion batteries and computational approaches to better understand their thermodynamic properties are included. Finally, K-ion batteries are compared to competing Li and Na systems and pragmatic opportunities and future research directions are discussed.
556 citations
TL;DR: In this article, the use of a flexible electrode based on free-standing graphene paper, to be applied in lithium rechargeable batteries was proposed. And the results showed that the graphene-based flexible electrode exhibits significantly improved performances in electrochemical properties, such as in energy density and power density.
Abstract: Recently, great interest has been aroused in flexible/bendable electronic equipment such as rollup displays and wearable devices. As flexible energy conversion and energy storage units with high energy and power density represent indispensable components of flexible electronics, they should be carefully considered. However, it is a great challenge to fabricate flexible/bendable power sources. This is mainly due to the lack of reliable materials that combine both electronically superior conductivity and mechanical flexibility, which also possess high stability in electrochemical environments. In this work, we report a new approach to flexible energy devices. We suggest the use of a flexible electrode based on free-standing graphene paper, to be applied in lithium rechargeable batteries. This is the first report in which graphene paper is adopted as a key element applied in a flexible lithium rechargeable battery. Moreover graphene paper is a functional material, which does not only act as a conducting agent, but also as a current collector. The unique combination of its outstanding properties such as high mechanical strength, large surface area, and superior electrical conductivity make graphene paper, a promising base material for flexible energy storage devices. In essence, we discover that the graphene based flexible electrode exhibits significantly improved performances in electrochemical properties, such as in energy density and power density. Moreover graphene paper has better life cycle compared to non-flexible conventional electrode architecture. Accordingly, we believe that our findings will contribute to the full realization of flexible lithium rechargeable batteries used in bendable electronic equipments.
542 citations
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Journal Article•
28,685 citations
TL;DR: The notion of sustainability is introduced through discussion of the energy and environmental costs of state-of-the-art lithium-ion batteries, considering elemental abundance, toxicity, synthetic methods and scalability.
Abstract: Energy storage using batteries offers a solution to the intermittent nature of energy production from renewable sources; however, such technology must be sustainable. This Review discusses battery development from a sustainability perspective, considering the energy and environmental costs of state-of-the-art Li-ion batteries and the design of new systems beyond Li-ion. Images: batteries, car, globe: © iStock/Thinkstock.
5,271 citations
TL;DR: In this article, a review of the key technological developments and scientific challenges for a broad range of Li-ion battery electrodes is presented, and the potential/capacity plots are used to compare many families of suitable materials.
5,057 citations
4,311 citations
TL;DR: Approaches, Derivatives and Applications Vasilios Georgakilas,† Michal Otyepka,‡ Athanasios B. Bourlinos,† Vimlesh Chandra, Namdong Kim, K. Kim,§,⊥ Radek Zboril,*,‡ and Kwang S. Kim.
Abstract: Approaches, Derivatives and Applications Vasilios Georgakilas,† Michal Otyepka,‡ Athanasios B. Bourlinos,‡ Vimlesh Chandra, Namdong Kim, K. Christian Kemp, Pavel Hobza,‡,§,⊥ Radek Zboril,*,‡ and Kwang S. Kim* †Institute of Materials Science, NCSR “Demokritos”, Ag. Paraskevi Attikis, 15310 Athens, Greece ‡Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University Olomouc, 17. listopadu 12, 771 46 Olomouc, Czech Republic Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, Pohang 790-784, Korea Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo naḿ. 2, 166 10 Prague 6, Czech Republic
3,460 citations