@article{oai:tsukuba.repo.nii.ac.jp:00033784,
 author = {石田, 政義 and Guo, Shaohua and Yu, Haijun and Liu, Pan and Ren, Yang and Zhang, Tao and Chen, Mingwei and Ishida, Masayoshi and Zhou, Haoshen},
 issue = {4},
 journal = {Energy & Environmental Science},
 month = {Apr},
 note = {Based on low-cost and rich resources, sodium-ion batteries have been regarded as a promising candidate for next-generation energy storage batteries in the large-scale energy applications of renewable energy and smart grids. However, there are some critical drawbacks limiting its application, such as safety and stability problems. In this work, a stable symmetric sodium-ion battery based on the bipolar, active O3-type material, Na0.8Ni0.4Ti0.6O2, is developed. This bipolar material shows a typical O3-type layered structure, containing two electrochemically active transition metals with redox couples of Ni4+/Ni2+ and Ti4+/Ti3+, respectively. This Na0.8Ni0.4Ti0.6O2-based symmetric cell exhibits a high average voltage of 2.8 V, a reversible discharge capacity of 85 mA h g−1, 75% capacity retention after 150 cycles and good rate capability. This full symmetric cell will greatly contribute to the development of room-temperature sodium-ion batteries with a view towards safety, low cost and long life, and it will stimulate further research on symmetric cells using the same active materials as both cathode and anode.},
 pages = {1237--1244},
 title = {High-performance symmetric sodium-ion batteries using a new, bipolar O3-type material, Na0.8Ni0.4Ti0.6O2},
 volume = {8},
 year = {2014}
}