Towards Watt-scale hydroelectric energy harvesting by Ti3C2Tx-based transpiration-driven electrokinetic power generators. Issue 1 (25th October 2021)

• Record Type: Journal Article
• Authors: Bae, Jaehyeong; Kim, Min Soo; Oh, Taegon; Suh, Bong Lim; Yun, Tae Gwang; Lee, Seungjun; Hur, Kahyun; Gogotsi, Yury; Koo, Chong Min; Kim, Il-Doo
• Is Part Of: Energy & environmental science. Volume 15:Issue 1(2022)
• Page Start: 123
• Page End: 135
• Publication Date: 2021-10-25
• Subjects: Energy conversion -- Periodicals; Fuel switching -- Periodicals; Environmental sciences -- Periodicals; Environmental chemistry -- Periodicals; 333.79
• DOI: 10.1039/d1ee00859e
• Languages: English
• ISSNs: 1754-5692

Abstract

Abstract : The use of Ti3 C2 T x MXenes/polyaniline composite tremendously improved the electrokinetic energy conversion efficiencies of nano-hydroelectric generators, demonstrating a power output sufficient to charge a commercial battery for the very first time. Abstract : Nano-hydroelectric technology utilizes hydraulic flow through electronically conducting nanomaterials to generate electricity in a simple, renewable, ubiquitous, and environmentally friendly manner. To date, several designs of nano-hydroelectric devices have been devised to maximize the electrokinetic interactions between water molecules and nanomaterials. However, the reported power generation of the state-of-the-art nano-hydroelectric generators is not sufficient for practical use, as tens of thousands of units were required to operate low-power electronics on a mW scale. Here, we utilize titanium carbide (Ti3 C2 T x ) MXene nanosheets, which have advantageous properties including metal-like conductivity and hydrophilicity, to facilitate the electrokinetic conversion of the transpiration–driven electrokinetic power generator (TEPG) with a remarkably improved energy generation efficiency compared to that of carbon-based TEPG. The Ti3 C2 T x MXene-based TEPG delivered a high pseudo-streaming current of 120 μA by the fast capillary flow promoted by MXene sheets coated on cotton fabric. The strong cationic affinity of Ti3 C2 T x enables the generator to achieve an output of 0.68 V and 2.73 mA when NaCl solution is applied. Moreover, incorporation of a conducting polymer (i.e., Ti3 C2 T x /polyaniline composite) enhanced the ionic diffusivity while maintaining the electrical network of Ti3 C2 T x . The optimized Ti3 C2 T x /polyaniline composite TEPG generated a maximum voltage of 0.54 V, a current of 8.2 mA, and a specific power density of 30.9 mW cm −3, which was sufficient to successfully charge a commercial Li-ion battery as well as low-power electronics and devices with a volume of 6.72 cm 3 .