MXene Hollow Microsphere-Boosted Nanocomposite Electrodes for Thermocells with Enhanced Thermal Energy Harvesting Capability.

Thermal energy, constantly being produced in natural and industrial processes, constitutes a significant portion of energy lost through various inefficiencies. Employing the thermogalvanic effect, thermocells (TECs) can directly convert thermal energy into electricity, representing a promising energy-conversion technology for efficient, low-grade heat harvesting. However, the use of high-cost platinum electrodes in TECs has severely limited their widespread adoption, highlighting the need for more cost-effective alternatives that maintain comparable thermoelectrochemical performance.

Rescuing zinc anode-electrolyte interface: mechanisms, theoretical simulations and characterizations.

The research interest in aqueous zinc-ion batteries (AZIBs) has been surging due to the advantages of safety, abundance, and high electrochemical performance. However, some technique issues, such as dendrites, hydrogen evolution reaction, and corrosion, severely prohibit the development of AZIBs in practical utilizations. The underlying mechanisms regarding electrochemical performance deterioration and structure degradation are too complex to understand, especially when it comes to zinc metal anode-electrolyte interface.

Coordinating zincophilic sites and a solvation shell for a dendrite-free Zn anode under the synergistic effects of polyacrylonitrile and dimethyl sulfoxide.

The advantages of aqueous zinc-ion batteries (AZIBs) are largely offset by the dendrite growth on the Zn anode, which is induced by the heterogeneous electrical field and limited ion transport of the Zn anode-electrolyte interface during plating and stripping. Here, we propose a dimethyl sulfoxide (DMSO)-HO hybrid electrolyte containing polyacrylonitrile (PAN) additives (PAN-DMSO-HO) to improve the electrical field and ion transport of the Zn anode, which can thus effectively inhibit dendrite growth. Experimental characterization and theoretical calculations show that PAN preferentially adsorbs on the Zn anode surface and provides abundant zincophilic sites after its solubilization by the DMSO, enabling a balanced electric field and lateral Zn plating.

Sulfonic-Group-Grafted TiCT MXene: A Silver Bullet to Settle the Instability of Polyaniline toward High-Performance Zn-Ion Batteries.

Polyaniline (PANI) is a promising cathode material for Zn-ion batteries (ZIBs) due to its intrinsic conductivity and redox activity; however, the achievements of PANI in high-performance ZIBs are largely hindered by its instability during the repeated charge/discharge. Taking advantage of the high conductivity, flexibility, and grafting ability together, a surface-engineered TiCT MXene is designed as a silver bullet to fight against the deprotonation and swelling/shrinking issues occurring in the redox process of PANI, which are the origins of its instability. Specifically, the sulfonic-group-grafted TiCT(S-TiCT) continuously provides protons to improve the protonation degree of PANI and maintains the polymer backbone at a locally low pH, which effectively inhibits deprotonation and brings high redox activity along with good reversibility.