Design & Development of Powerful Next Generation Layered Cathode Materials for Na-Ion Batteries

Sodium-Ion Batteries (SIBs) have established themselves as possible low-cost alternative to the common lithium-ion battery (LIB). The cost advantage is underlined by a powerful electrochemical performance, superior to any other secondary battery except for LIBs. Consequently, this has led to a rapidly increasing scientific interest within the last five years. In accordance with the economical concept of diversification SIBs are discussed to be promising alternative for applications, in which cost-efficient energy storage (in terms of $/kWh) is the most important criterion. In order to boost SIBs into such applications (e.g. for the decentralized and fragmented power grid of the future) new, powerful but also rather cheap materials composed of abundant and environmentally friendly elements, need to be used in order to cover the lower electrochemical performance. In fact, research community and research efforts are, currently, focusing on the material screening and development. [1-3]

With respect to layered materials strong progress in terms of their understanding, characterization and their performance has been achieved. In this presentation we will focus on the design and development of layered cathode materials for powerful next generation SIBs.

In the past, we have synthesized and characterized layered P2- Na_xNi_0.22Co_0.11Mn_0.66O₂material. [4-6] In this presentation we will show how the composition of this material can be modified and reveal the effect on the electrochemical performance.[7-9] Final intention of the presentation is to:

-illustrate the influence of the composition on the electrochemical performance,

-illustrate how layered cathode materials can be designed,

-demonstrate the feasibility of these principals via a new layered Na- based oxide.

The final material delivers a stable capacity of about 110 mAh g^-1 (3.4 V average discharge potential) at a high current rate of 1C (180 mA g^‑1) between 4.3-2.5 V (vs. Na/Na⁺) in conventional organic carbonate based electrolyte. This performance is among the best reported for layered Na-based oxides so far and certainly is promising for the application in future Na-based electrochemical energy storage devices.

[1] S.-W. Kim et al. Adv. Energy Mater. 2 (2012), 710.

[2] J.M. Tarascon Nature Chemistry 2 (2010), 510.

[3] N. Yabuuchi et al. Chem. Rev. 114 (2014), 11636.

[4] D. Buchholz et al. Chem. Mater. 25 (2013), 142.

[5] D. Buchholz et al. J. Mater. Chem. A 2 (2014), 13415.

[6] L.G. Chagas et al. J. Mater. Chem. A 2 (2014) 20263.

[7] I. Hasa et al. Adv. Energy Mater. 4 (2014), 140083.

[8] I. Hasa et al. ACS Appl. Mater. Interfaces 7 (2015), 5206.

[9] D. Buchholz et al. J. Power Sources 282 (2015), 581.