An article titled “Experimental and theoretical studies of trisodium-1,3,5- benzene tricarboxylate as a low voltage anode material for sodium ion batteries” authored by A. Tripathi, Y. Chen, H. Padhy, S. Manzhos and P. Balaya, has been accepted for publication in Energy Technology. [DOI: 10.1002/ente.201801030]

Abstract

We report a tricarboxylate based organic compound for Na storage at low voltage, trisodium‐1,3,5‐benzene tricarboxylate (Na3BTC). We explore the effect of increasing the number of carboxyl redox active groups on the aromatic system versus previously reported dicarboxylate‐based Na electrodes. Sodiation and de‐sodiation of this material occur at average voltages of 0.4 V and 0.5 V, respectively, suitable for anode application. The galvanostatic profile of de‐sodiation consists of two plateaus at 0.5 V and 0.2 V. The material delivers a capacity of 250 mAh g‐1 at C/5 rate, with retention of 80% after 100 cycles. It also has an excellent rate capability delivering 100 mAh g‐1 with 75% retention after 1,500 cycles at 10 C rate. Ex‐situ ATR‐FTIR, ex‐situ 1H NMR studies as well as first principles calculations are performed to understand the sodium storage mechanism. The mechanism is found to be different from those previously observed in lithium dicarboxylates and sodium dicarboxylates in that there is apparently almost no charge donation from the inserted Na to the organic moiety.