P2- Type NaNi1/3Mn2/3-XZnxO2: As a Cathode Material for Na-Ion Cells

Since 1990s Li-ion batteries (LIBs) are playing a vital role in portable electronic devices (1-2) such as mobiles, laptops, tablets, and electric vehicles etc., owing to its compact size and high energy density. However, the main problem of lithium is its abundance and cost deters it from making cost-effective battery. Therefore, researchers (3 – 5) are considering alternatives like Na-ion battery chemistry as sodium is the one of most abundant element in the earth crust and its redox potential close to lithium. In the present work, we report the synthesis and characterization of NaNi_1/3Mn_2/3-xZn_xO₂, by using citric acid assisted sol-gel method for use as cathode material in Na-ion battery. Here, citric acid acts both as a fuel and chelating agent. XRD analysis reveals that the P2 type layered structure as depicted in Fig.1 for NaNi_1/3Mn_2/3O_2, NaNi_1/3Mn_2/3-xZn_xO₂. SEM studies of NaNi_1/3Mn_2/3O_2, NaNi_1/3Mn_2/3-xZn_xO₂ are confirms that, particle size range is about 1-2 m with different shapes which is shown in Fig., 2 (a, b). Electro chemical studies have been performed between 2.0 - 4.3 V for a Na/ NaNi_1/3Mn_2/3-xZn_xO₂   system, here sodium is reference as well as counter electrode assembled in CR-2032 type coin cells using 1M NaClO₄ EC: DEC (1:1 V/V) electrolyte medium. 

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