Process‐Structure‐Formulation Interactions for Enhanced Sodium Ion Battery Development: A Review

Abstract

Before the viability of a cell formulation can be assessed for implementation in commercial sodium ion batteries, processes applied in cell production should be validated and optimized. This review summarizes the steps performed in constructing sodium ion (Na‐ion) cells at research scale, highlighting parameters and techniques that are likely to impact measured cycling performance. Consistent process‐structure‐performance links have been established for typical lithium‐ion (Li‐ion) cells, which can guide hypotheses to test in Na‐ion cells. Liquid electrolyte viscosity, sequence of mixing electrode slurries, rate of drying electrodes and cycling characteristics of formation were found critical to the reported capacity of laboratory cells. Based on the observed importance of processing to battery performance outcomes, the current focus on novel materials in Na‐ion research should be balanced with deeper investigation into mechanistic changes of cell components during and after production, to better inform future designs of these promising batteries.

Mixing, Fast and Slow: Assessing the Efficiency of Electronically Conductive Networks in Hard Carbon Anodes

“…The multivariate nature of these physicochemical interactions has been well-described for typical electrodes used in Li-ion cells [26,27]. Comparably fewer studies have been published about the requirements for conductive additives in Na-ion electrodes [28]. Optimizing the amount of conductive additive added into an anode formula therefore depends not only on the particle characteristics of the additive but also on slurry mixing parameters, binder properties and particle characteristics of the active material.…”

“…The multivariate nature of these physicochemical interactions has been well-described for typical electrodes used in Li-ion cells [26,27]. Comparably fewer studies have been published about the requirements for conductive additives in Na-ion electrodes [28].…”

A NiCoSex/CG heterostructure with strong interfacial interaction showing rapid diffusion kinetics as a flexible anode for high-rate sodium storage

“…[3][4][5][6] However, because of the larger radius and lower standard electrochemical potential of sodium ions compared with those of lithium ions, the speed of sodium ions embedding into the electrode material is slow, which hinders the development of the anode electrode of sodium ion batteries (SIBs). [7][8][9][10] In recent years, based on the existing lithium-ion battery technology, there have been a lot of studies trying to apply alloys and transition metal compounds to SIBs, 11 but this kind of anode material tends to expand in volume during the process of sodiation/desodiation, resulting in poor cycling stability. [12][13][14][15] Therefore, a new anode material with a higher rate capacity and more stable structure needs to be prepared through reasonable design and precise control.…”

Flexible NiSe2/CoSe2 heterostructure with rapid diffusion kinetics as binder-free anode for high-rate sodium ion batteries

“…[1][2][3][4] However, because the lager radius (1.02 Å for Na vs 0.76 Å for Li) and low standard electrochemical potential (2.71 V for Na + /Na vs 3.04 V for Li + /Li) of sodium ion compared with those of lithium ion, the speed of sodium ion embedding into the electrode material is slow, which hinders the development of the anode electrode of sodium ion batteries (SIBs) due to the low power and energy densities. [5][6][7][8] In recent years, based on the existing lithium-ion battery technology, there have been a lot of studies trying to apply alloys and transition metal compound to SIBs, but this kind of anode materials tend to expand in volume during the process of sodiation/desodiation, resulting in poor cycle stability. [9][10][11][12] Therefore, a new anode material with higher rate capacity and more stable structure needs to be prepared through reasonable design and precise control.…”