Nanocellulose‐Carboxymethylcellulose Electrolyte for Stable, High‐Rate Zinc‐Ion Batteries

Abstract

Aqueous Zn ion batteries (ZIBs) are one of the most promising battery chemistries for grid-scale renewable energy storage. However, their application is limited by issues such as Zn dendrite formation and undesirable side reactions that can occur in the presence of excess free water molecules and ions. In this study, a nanocellulose-carboxymethylcellulose (CMC) hydrogel electrolyte is demonstrated that features stable cycling performance and high Zn 2+ conductivity (26 mS cm −1 ), which is attributed to the material's strong mechanical strength (≈70 MPa) and water-bonding ability. With this electrolyte, the Zn-metal anode shows exceptional cycling stability at an ultra-high rate, with the ability to sustain a current density as high as 80 mA cm −2 for more than 3500 cycles and a cumulative capacity of 17.6 Ah cm −2 (40 mA cm −2 ). Additionally, side reactions, such as hydrogen evolution and surface passivation, are substantially reduced due to the strong water-bonding capacity of the CMC. Full Zn||MnO 2 batteries fabricated with this electrolyte demonstrate excellent high-rate performance and long-term cycling stability (>500 cycles at 8C). These results suggest the cellulose-CMC electrolyte as a promising low-cost, easy-to-fabricate, and sustainable aqueous-based electrolyte for ZIBs with excellent electrochemical performance that can help pave the way toward grid-scale energy storage for renewable energy sources.

The role of oxygen vacancies in the performance of LiMn2O4 spinel cathodes for lithium-ion batteries

“…1–5 As the decisive part of lithium-ion batteries, cathode materials play a crucial role in the capacity, cell voltage, energy density, safety and cycle life. 6–9 Until now, many possible cathode materials have been extensively and intensively studied for electric vehicle applications, mainly layered transition metal oxides (TMOs), manganese-based oxides, phosphates, and silicate materials. 10…”

Polycation‐Regulated Electrolyte and Interfacial Electric Fields for Stable Zinc Metal Batteries

“…Nevertheless, unbounded dendrite growth, corrosion and passivation of zinc (Zn) metal anodes, resulting in low coulombic efficiency (CE) and limited lifetime, which may lead to battery short circuit, is one of the most crucial obstacles for the development of aqueous ZIBs [6–12] . Several strategies have been executed to enhance the electrochemical stability of Zn metal anodes by inhibiting the dendrite formation and banishing the water‐induced parasitic reaction, including electrolyte regulation, interfacial manipulation, substrate modification, etc [13–26] . Among these strategies, electrolyte formulation plays a vital role in regulating the Zn deposition behavior and diminishing the side reaction on Zn metal anodes, because of its effectiveness, simple procedure, and easy implementation [27–29] …”

“…[6][7][8][9][10][11][12] Several strategies have been executed to enhance the electrochemical stability of Zn metal anodes by inhibiting the dendrite formation and banishing the water-induced parasitic reaction, including electrolyte regulation, interfacial manipulation, substrate modification, etc. [13][14][15][16][17][18][19][20][21][22][23][24][25][26] Among these strategies, electrolyte formulation plays a vital role in regulating the Zn deposition behavior and diminishing the side reaction on Zn metal anodes, because of its effectiveness, simple procedure, and easy implementation. [27][28][29] Usually, Zn dendrite growth involves reduplicative processes of nucleation and deposition/dissolution.…”

“…[10,21,48,49] However, the ex situ construction of these electrolytes and coatings are usually complicated and associated with serious interface problems. [19,20] Up to now, little attention was paid to the fundamental problems of polymers as additives, especially polyelectrolytes, in improving Zn metal anode stability. More importantly, the relationship between the positive/negative charge polar groups of polyelectrolytes and the Zn 2 + solvation structure, the Zn 2 + transport and deposition kinetics, and the formation of Zn anode interphase as well as the underlying mechanism has never been revealed.…”

“…On the other hand, polymers with large skeleton and abundant functional groups are usually used to construct solid polymer electrolytes, quasi‐solid gel electrolytes or functional coatings to improve ion flux and transport, and alleviate the disordered deposition of ions and parasitic reaction [10, 21, 48, 49] . However, the ex situ construction of these electrolytes and coatings are usually complicated and associated with serious interface problems [19, 20] . Up to now, little attention was paid to the fundamental problems of polymers as additives, especially polyelectrolytes, in improving Zn metal anode stability.…”