PROGRESS REPORT 1803444 (1 of 20) © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim www.advmat.de Rational Design of Carbon Nanomaterials for Electrochemical Sodium Storage and Capture Jiyoung Kim, Min Sung Choi, Kang Ho Shin, Manikantan Kota, Yingbo Kang, Soojung Lee, Jun Young Lee,* and Ho Seok Park* Dr. J. Kim, M. S. Choi, K. H. Shin, M. Kota, Y. Kang, S. Lee, Prof. J. Y. Lee, Prof. H. S. Park School of Chemical Engineering Sungkyunkwan University (SKKU) 2066 Seobu-ro, Jangan-gu, Suwon 16419, Republic of Korea E-mail: jylee7@skku.edu; phs0727@skku.edu Prof. H. S. Park Department of Health Sciences and Technology Samsung Advanced Institute for Health Sciences and Technology (SAIHST) Sungkyunkwan University (SKKU) 2066 Seobu-ro, Jangan-gu, Suwon 16419, Republic of Korea The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/adma.201803444. DOI: 10.1002/adma.201803444 change problems, transition into renew- able energy system is no optional choice longer. Sodium can be used as a chemical energy that can be stored and released through an electrochemical charging/ discharging process. In particular, elec- trochemical sodium storage and capture technologies are very critical for resolving the aforementioned issues, because sodium is abundant with uniformly geo- metrical distribution and electrochemical systems are more efficient and environ- mentally friendly than conventional heat engine using fossil fuels. [5] Electrochemical energy storage devices can be classified into batteries and supercapacitors (SCs) depending on charge storage mechanisms. Batteries can store and release charges in an internal structure of active materials through a far- adaic process with a phase transformation of bulk, while SCs can store and release charges at a surface of active material through either a faradaic (for pseudoca- pacitor) or nonfaradaic (for electrochem- ical double-layer capacitor, EDLC) process. These two devices have pros and cons due to these intrinsic charge storage mech- anisms. [6] On the one hand, batteries have high energy density. However, they have low power density and short cyclic life. On the other hand, SCs have advantages such as high power and cyclic capabilities. However, they also have the disadvantage of low energy density. For renewable energy storage system (ESS), commercialized lithium-ion batteries (LIBs) are candidates due to their higher energy densities compared to other energy storage devices. [7–9] However, current LIBs cannot satisfy require- ments of industrial scale ESS such as low cost and safety due to scarcity of lithium and chemical stability. [10] Sodium-ion batteries (SIBs) are strong candidates to replace current LIBs for large scale ESS owing to the huge abundance (the fourth abundant metallic element, around 23 600 ppm against 20 ppm for lithium in the each cluster [11] ) and low supply cost (about US$135–165 per ton against US$5000 per ton for lithium [12] ) of sodium as well as its safety. The copper current collect can be replaced by the cheaper and lighter aluminum. Moreover, well-established technologies and infrastructures of LIBs can be utilized because of the electrochemical similarity of two bat- teries. [13–16] This situation is similar to the field of SC based on sodium ion, the so-called sodium-ion capacitor (SIC). Despite Electrochemical sodium storage and capture are considered an attractive technology owing to the natural abundance, low cost, safety, and cleanness of sodium, and the higher efficiency of the electrochemical system compared to fossil-fuel-based counterparts. Considering that the sodium-ion chemistry often largely deviates from the lithium-based one despite the physical and chemical similarities, the architecture and chemical structure of electrode materials should be designed for highly efficient sodium storage and capture technologies. Here, the rational design in the structure and chemistry of carbon materials for sodium-ion batteries (SIBs), sodium-ion capacitors (SICs), and capacitive deionization (CDI) applications is comprehensively reviewed. Types and features of carbon materials are classified into ordered and disor- dered carbons as well as nanodimensional and nanoporous carbons, covering the effect of synthesis parameters on the carbon structure and chemistry. The sodium storage mechanism and performance of these carbon materials are correlated with the key structural/chemical factors, including the inter- layer spacing, crystallite size, porous characteristics, micro/nanostructure, morphology, surface chemistry, heteroatom incorporation, and hybridization. Finally, perspectives on current impediment and future research directions into the development of practical SIBs, SICs, and CDI are also provided. Nanostructured Carbon 1. Introduction Energy, environment, and water are three critical problems among 10 crises that mankind is currently facing. [1] Due to accelerating population growth and fossil fuel consumption, three threatening issues are getting more severe. [2–4] Consid- ering that renewable energy is essential for resolving energy and natural resource depletion, global warming, and climate Adv. Mater. 2019, 1803444