Overview

Sodium ion batteries (SIBs) are considered as potential alternative to Lithium ion batteries (LIBs) for large scale energy storage applications, such as grid energy storage and electric vehicle (EV) applications due to abundance of sodium, high specific energy and low-cost. However, plenty of research efforts are required to find suitable electrodes and electrolytes to achieve specific energy similar to that of LIBs. Hence, different electrode materials are selected based on their promising electrochemical performances. Polyanionic compounds with long cycle life and layered sodium transition metal oxides with high specific capacity as cathodes; whereas hard carbon and sodium titanates with low sodium insertion potential and high specific capacity as anodes have been prepared using novel chemical approaches and their electrochemical performances have been investigated using indigenously developed non-aqueous based electrolyte. Full cells (Pouch-type) have been fabricated using polyanionic compound (here, sodium vanadium phosphate) as cathode and hard carbon as anode and the electrochemical studies are under progress.

Key Features

  • High specific energy and power density, good rate capability, excellent cycle life, high thermal stability and safe-in operation.
  • Low- cost and wider operating temperature range.

Potential Applications

  • Large scale electric energy storage (EES)
  • Stationary energy storage
  • Electric/hybrid electric vehicles

Status

  • Electrolytes with high ionic conductivity (>10-3 S/cm) and electrochemical stability window (>4.2 V) has been prepared and tested.
  • Electrode materials with excellent sodium ion storage performance has been developed, where cycle life >1000 cycles has been demonstrated in full cell configuration.
  • Optimization of large scale synthesis (500 g/batch) and pouch cell fabrication (1 Ah) are under progress.
(a) TEM image of in-situ carbon coated Na3V2(PO4)3 (NVP) nanoparticle embedded in mesoporous carbon matrix;(b) Specific capacity vs. cycle number plot for carbon coated NVP against sodium metal at 1C-rate when cycled between 2.3-3.9 V.
(c) Specific capacity vs. cycle number plot for carbon coated NVP symmetric full cell at 1 A/g (8.49 C-rate) when cycled between 0-3.0 V

  • Microwave assisted sol-gel process for preparing in-situ carbon coated electrode materials and the product there of,” (2019) Bijoy Kumar Das, P. Laxman Manikanta, N. Lakshmipriya, R. Gopalan, G. Sundararajan, Indian Patent 201911008004.
  • Microwave assisted sol-gel process for preparing in-situ carbon coated electrode materials and the product thereof”, (2020) Bijoy Kumar Das, P. Laxman Manikanta, N. Lakshmipriya, R. Gopalan, G. Sundararajan, European Patent: 20763813.1
  • Microwave assisted sol-gel process for preparing in-situ carbon coated electrode materials and the product thereof”, (2020) Bijoy Kumar Das, P. Laxman Manikanta, N. Lakshmipriya, R. Gopalan, G. Sundararajan, Japanese Patent: 2020-550159
  • Microwave assisted sol-gel process for preparing in-situ carbon coated electrode materials and the product thereof”, (2020) Bijoy Kumar Das, P. Laxman Manikanta, N. Lakshmipriya, R. Gopalan, G. Sundararajan, Korean Patent: 10-2020-7025994

  • Scalable synthesis and kinetic studies of carbon coated sodium titanate: A promising ultra-low intercalation voltage anode for sodium ion battery”, P. Laxman Mani Kanta, M. Venktesh, Satyesh Kumar Yadav, Bijoy Kumar Das*, R. Gopalan, Trans. Ind. Nation. Acad. Eng. 5 (2020) 475-483.