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Sodium Ion Batteries using Ionic Liquids as Electrolytes
Author(s) -
Hagiwara Rika,
Matsumoto Kazuhiko,
Hwang Jinkwang,
Nohira Toshiyuki
Publication year - 2019
Publication title -
the chemical record
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.61
H-Index - 78
eISSN - 1528-0691
pISSN - 1527-8999
DOI - 10.1002/tcr.201800119
Subject(s) - electrolyte , ionic liquid , gravimetric analysis , sodium , chemistry , lithium (medication) , energy storage , battery (electricity) , inorganic chemistry , electrode , chemical engineering , ionic bonding , ion , organic chemistry , catalysis , thermodynamics , medicine , power (physics) , physics , engineering , endocrinology
Abstract Sodium ion batteries have been developed using ionic liquids as electrolytes. Sodium is superior to lithium as a raw material for mass production of large‐scale batteries for energy storage due to its abundance and even distribution across the earth. Ionic liquids are non‐volatile and non‐flammable, which improved the safety of the batteries remarkably. In addition, operation temperatures were extended to higher values, improving the performance of the batteries by facilitating the reaction at the electrode and mass transfer. Binary systems of sodium and quaternary ammonium salts, such as 1‐ethyl‐3‐methylimidazolium and N ‐methyl‐ N ‐propylpyrrolidinium bis(fluorosulfonyl)amide, were employed as electrolytes for sodium ion batteries. A series of positive and negative electrode materials were examined to be combined with these ionic liquid electrolytes. A 27 Ah full cell was fabricated employing sodium chromite (NaCrO 2 ) and hard carbon as positive and negative electrode materials, respectively. The gravimetric energy density obtained for the battery was 75 Wh kg −1 and its volumetric energy density was 125 Wh L −1 . The capacity retention after 500 cycles was 87 %. Further improvement of the cell performance and energy density is expected on development of suitable electrode materials and optimization of the cell design.