Fine Tuning Water States in Hydrogels for High Voltage Aqueous Batteries

Li，Chuan1,2; Zhu，Xiaohong2; Wang，Donghong3,5; Yang，Shuo2; Zhang，Rong2; Li，Pei2; Fan，Jun2; Li，Hongfei1,6; Zhi，Chunyi1,2,3,4

2024-01-30

10.1021/acsnano.3c08398

ACS Nano   影响因子和分区

1936-0851

1936-086X

Hydrogels are widely used as quasi-solid-state electrolytes in aqueous batteries. However, they are not applicable in high-voltage batteries because the hydrogen evolution reaction cannot be effectively suppressed even when water is incorporated into the polymer network. Herein, by profoundly investigating the states of water molecules in hydrogels, we designed supramolecular hydrogel electrolytes featuring much more nonfreezable bound water and much less free water than that found in conventional hydrogels. Specifically, two strategies are developed to achieve this goal. One strategy is adopting monomers with a variety of hydrophilic groups to enhance the hydrophilicity of polymer chains. The other strategy is incorporating zwitterionic polymers or polymers with counterions as superhydrophilic units. In particular, the nonfreezable bound water content increased from 0.129 in the conventional hydrogel to >0.4 mg mg in the fabricated hydrogels, while the free water content decreased from 1.232 to ∼0.15 mg mg. As a result, a wide electrochemical stability window of up to 3.25 V was obtained with the fabricated hydrogels with low concentrations of incorporated salts and enhanced hydrophilic groups or superhydrophilic groups. The ionic conductivities achieved with our developed hydrogel electrolytes were much higher than those in the conventional highly concentrated salt electrolytes, and their cost is also much lower. The designed supramolecular hydrogel electrolytes endowed an aqueous K-ion battery (AKIB) system with a high voltage plateau of 1.9 V and contributed to steady cycling of the AKIB for over 3000 cycles. The developed supramolecular hydrogel electrolytes are also applicable to other batteries, such as aqueous lithium-ion batteries, hybrid sodium-ion batteries, and multivalent-ion aqueous batteries, and can achieve high voltage output.

aqueous batteries high voltage hydrogel electrolyte low concentration of salts water states

SCI ; EI

英语

其他

2-s2.0-85183475107

Scopus

1.Songshan Lake Materials Laboratory,Dongguan,Guangdong,523808,China
2.Department of Materials Science and Engineering,City University of Hong Kong,Kowloon,999077,Hong Kong
3.Hong Kong Center for Cerebro-Cardiovascular Health Engineering (COCHE),Shatin,NT,999077,Hong Kong
4.Hong Kong Institute for Clean Energy,City University of Hong Kong,Kowloon,999077,Hong Kong
5.School of Materials Science and Engineering,Anhui University of Technology,Ma’anshan,Anhui,243032,China
6.School of System Design and Intelligent Manufacturing,Southern University of Science and Technology,Shenzhen,Guangdong,518055,China

Li，Chuan,Zhu，Xiaohong,Wang，Donghong,et al. Fine Tuning Water States in Hydrogels for High Voltage Aqueous Batteries[J]. ACS Nano,2024,18(4):3101-3114.

Li，Chuan.,Zhu，Xiaohong.,Wang，Donghong.,Yang，Shuo.,Zhang，Rong.,...&Zhi，Chunyi.(2024).Fine Tuning Water States in Hydrogels for High Voltage Aqueous Batteries.ACS Nano,18(4),3101-3114.

Li，Chuan,et al."Fine Tuning Water States in Hydrogels for High Voltage Aqueous Batteries".ACS Nano 18.4(2024):3101-3114.