Na‐Ion Batteries—Approaching Old and New Challenges

Abstract

are proving to be an emergent technology with potentially very attractive properties. They are potentially low cost and environmentally friendly with reduced supply risk. However, the development of NIBs faces various challenges such as low gravimetric and volumetric energy densities and difficulty in achieving broader voltage windows. Although early studies in NIBs date back to the 1970s, just like Li-ion battery (LIB) research, the commercialization of the former systems in 1991 by the team formed by Sony and Asahi Kasei marked a milestone not only in the field of energy storage technology but also in the evolution of the modern society. This technological breakthrough had been possible thanks to several preceding contributions, particularly the works by M. S Whittingham, [1] J. Goodenough, [2,3] and A. Yoshino [4] on the discovery of Li-ion intercalation materials (Nobel Laureates in Chemistry 2019). This important historical event polarized material science research toward Li-ion technology and slowed down considerably the advances in the field of sodium. However, at the end of the 2000s, mainly driven by the concerns about future lithium supply and the uneven worldwide distribution of its reserves and resources, the research on Na-ion reemerged and so did the number of articles published (Figure 1). The intercalation chemistry of both metal ions is very alike, and thus, the materials tested for NIBs could be similar to those used in Li-ion systems. Both systems share the same working principle, and therefore, in terms of manufacturing, the industry producing LIBs can be easily tuned towards NIB fabrication, which is an important asset to invest in and support this technology. NIBs started to reach the market in the early 2010s, about two decades after their Li counterparts. Nevertheless, the progress has been relatively fast due to the straightforward LIB equipment and facility transfer just mentioned. In the search of high performance, low cost, abundance, low environmental impact, long-term cyclability and safety, layered metal oxides, polyanionic compounds and Prussian blue analogues (PBAs) are among the most studied families of Na-ion cathode materials. On the anode side, metallic sodium exhibits the same operation and safety problems as lithium, and therefore, it cannot be considered an option in conventional NIBs. Thus, in this scenario, most of the research has been dominated by the use of disordered carbons, mainly hard carbons (HCs). Other prospective anodes

Structural Aspects of P2‐Type Na0.67Mn0.6Ni0.2Li0.2O2 (MNL) Stabilization by Lithium Defects as a Cathode Material for Sodium‐Ion Batteries

“…For example, van der Ven and coworkers favor Mn redox over O redox based on theoretical studies. [ 44 ] On the other hand, it is also important to stress that a complete theoretical treatment of layered oxides with vacancies and mixed occupations on several sites accompanied by the partial oxidation of oxygen anions is challenging due to their complexity. Impurities due to CO 2 (formation of carbonates during calcination) and water (e.g., OH – instead of O 2– at the surface, protons) can also alter the materials properties as well but we do not believe that the surface effects can impact the main conclusions from our calculations.…”

Hunting Sodium Dendrites in NASICON-Based Solid-State Electrolytes

“…Na-ion batteries (NIBs) have been investigated broadly for the potential application particularly in large-scale electrical energy storage due to the infinite sodium resources and relatively low cost [1][2][3][4][5][6]. Owning to its low electrochemical potential of -2.71 V (vs. standard hydrogen electrode) and high specific capacity of 1166 mAh g -1 , Na metal becomes the most attractive anode for NIBs [4,5,[7][8][9].…”

Molecularly Compensated Pre‐Metallation Strategy for Metal‐Ion Batteries and Capacitors

“…P2-type sodium layered oxides) seriously hinders the practical application of rechargeable MIBs. [4] Thus,p re-metallation treatment could effectively replenish the losing active metal contents and further guarantee am aximum capacity.M ean-while,d ue to the physical adsorption/desorption behavior of porous carbon cathode without the required metal reservation, pre-metallation procedure for metal-ion capacitors (MICs) must be accomplished, which could enlarge the working voltage endowed by al ow potential of pre-metallated anode and reduce the electrolyte consumption during long-term cycling. [5] Furthermore,t he decreased electrolyte concentration could directly influence the ionic conductivity of electrolyte and thus reduce the electrochemical performances of MICs.…”