Water-mediated crystallohydrate\u2013polymer composite as a phase-change electrolyte

Ziyang Tai,Yinghui Shang,Junjie Wei,Chu Wu,Qigang Wang,Jie Zhou,Yue Liao,Baofeng Wang

doi:10.1038/s41467-020-15415-5

Ziyang Tai, Yinghui Shang + Show 6 more

Open Access

https://doi.org/10.1038/s41467-020-15415-5

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Abstract

With the world’s focus on wearable electronics, the scientific community has anticipated the plasticine-like processability of electrolytes and electrodes. A bioinspired composite of polymer and phase-changing salt with the similar bonding structure to that of natural bones is a suitable electrolyte candidate. Here, we report a water-mediated composite electrolyte by simple thermal mixing of crystallohydrate and polymer. The processable phase-change composites have significantly high mechanical strength and high ionic mobility. The wide operating voltage range and high faradic capacity of the composite both contribute to the maximum energy density. The convenient assembly and high thermal-shock resistance of our device are due to the mechanical interlocking and endothermic phase-change effect. As of now, no other non-liquid electrolytes, including those made from ceramics, polymers, or hydrogels, possess all of these features. Our work provides a universal strategy to fabricate various thermally manageable devices via phase-change electrolytes.

Highlights

With the world’s focus on wearable electronics, the scientific community has anticipated the plasticine-like processability of electrolytes and electrodes
Relative to complicated designs based on the principle of similar compatibility, an evaluation of nature shows exquisite designs of tough bone and seashell connected by crystal-surface-bound water as a transition phase to connect the organic and inorganic components that have a large surface energy difference[23,24,25]
The narrow operating voltage range and weak mechanical strength of traditional hydrogel electrolytes have limited their practical applications; in addition, ceramic and polymer electrolytes have been hindered by poor interfacial compatibility and low ionic conductivity, respectively[39,40]

Summary

Results

The crystal-surface-bound water layer in the system provided a synergistic relationship between the hardness of the ST crystal phase and the toughness of the polymer phase, especially when the mass ratio of ST and PAANa was in a range of 2–6. These crystallohydrate–polymer composites exhibited significantly high strength under pressure because of the compact crystal columns arranged in parallel (Fig. 2d). The high activity caused by the “jumping conduction” phenomenon and the presence of bound water in the PCCE system improved the low ionic conductivity of traditional solid polymer electrolytes, and the use of the hydrated crystalline salt provided similar strength to traditional inorganic electrolytes. It had better interfacial contact between the electrode and electrolyte than the conventional solid electrolyte due to strong interfacial a 0.6

A g–1 2 A g–1 4 A g–1 8 A g–1

Discussion

Methods