Eco-Efficient Synthesis of Highly Porous CoCO3Anodes from Supercritical CO2for Li+and Na+Storage.
An eco-efficient synthetic route for the preparation of high-performance carbonate anodes for Li+and Na+batteries is developed. With supercritical CO2(scCO2) as the precursor, which has gas-like diffusivity, extremely low viscosity, and near-zero surface tension, CoCO3particles are uniformly formed and tightly connected on graphene nanosheets (GNSs). This synthesis can be conducted at 50 °C, which is considerably lower than the temperature required for conventional preparation methods, minimizing energy consumption. The obtained CoCO3particles (ca. 20 nm in diameter), which have a unique interpenetrating porous structure, can increase the number of electroactive sites, promote electrolyte accessibility, shorten ion diffusion length, and readily accommodate the strain generated upon charging/discharging. With a reversible capacity of 1105 mAh g-1, the proposed CoCO3/GNS anode shows an excellent rate capability, as it can deliver 745 mAh g-1in 7.5 min. More than 98 % of the initial capacity is retained after 200 cycles. These properties are clearly superior to those of previously reported CoCO3-based electrodes for Li+storage, indicating the merit of our scCO2-based synthesis, which is facile, green, and can be easily scaled up for mass production.
Institute of Materials Science and Engineering, National Central University, Taoyuan, 32001, Taiwan, R.O.C.
Hui-Ying
HY
Li
Department of Materials Engineering, Ming Chi University of Technology, New Taipei City, 24301, Taiwan, R.O.C.
Chuan-Ming
CM
Tseng
Institute of Materials Science and Engineering, National Central University, Taoyuan, 32001, Taiwan, R.O.C.
Cheng-Hsien
CH
Yang
Department of Chemical and Materials Engineering, National Central University, Taoyuan, 32001, Taiwan, R.O.C.
Tai-Chou
TC
Lee
Institute of Energy Engineering, National Central University, Taoyuan, 32001, Taiwan, R.O.C.
Ching-Yuan
CY
Su
Department of Chemical Engineering and Materials Science, Yuan Ze University, Taoyuan, 320, Taiwan, R.O.C.
Chien-Te
CT
Hsieh
Institute of Materials Science and Engineering, National Central University, Taoyuan, 32001, Taiwan, R.O.C.|Department of Chemical and Materials Engineering, National Central University, Taoyuan, 32001, Taiwan, R.O.C.
Jeng-Kuei
JK
Chang
D002245:Carbon Dioxide; D002254:Carbonates / Q000737:chemistry; D003035:Cobalt / Q000737:chemistry; D011211:Electric Power Supplies / Q000592:standards*; D055664:Electrochemical Techniques; D055772:Green Chemistry Technology / Q000379:methods; D008094:Lithium / Q000737:chemistry*; D016062:Porosity; D012964:Sodium / Q000737:chemistry*
D002254:Carbonates; D002245:Carbon Dioxide; D003035:Cobalt; D008094:Lithium; D012964:Sodium
batteries; cobalt; energy storage; green chemistry; supercritical fluids