Lithium-sulfur (Li-S) batteries with high specific capacity are expected to be a new generation of energy storage devices. However, the shuttle effect of lithium polysulfide makes it difficult to commercialize stable Li-S batteries. In this work, we designed a gelatin-polyethylenimine composite (GPC) as functional binder for Li-S batteries to improve the stability of electrode during discharge-charge process. GPC binder combines the dispersion and adhesion ability of gelatin, which keeps cathode homogeneous and stable during electrochemical reaction , and adsorption capability of PEI for polysulfide , which suppresses the “shuttling effect”. The result shows that GPC used as a binder remarkably enhanced cyclic performance of Li-S battery with good capacity retention of about 100% at current density of 1C (sulfur loading 1.5 mg cm −2 ) after 100 cycles. We believe that GPC would be a promising binder for highly stable Li-S batteries.
Yingjun Qiao,Yonggan Ran,Zhiqiang Qian,Bing Zhao,Chengpeng Li,Zhong Liu
The Mn dissolution issue in manganese-based materials (LMO) represents one of the most challenging barriers to further commercial development of electrochemical lithium extraction, which is an efficient and clean way of extracting Li from liquid resources. Here, by leveraging the advantages of composite materials, a novel combination of reduced graphene oxide (rGO) and sulfonated ionic polymers (Nafion) is introduced to relieve the issues of electrode polarization and manganese dissolution, critical factors limiting the durability of LMO electrodes. By modifying with rGO to enhance electronic conductivity and surface characteristics, and capturing dissolved Mn 2+ through Nafion, the modified electrode showed significant improvement in cycling stability and lithium adsorption capacity. Experimental results confirm that this synergistic approach effectively mitigates polarization effects and controls disproportionation reactions, thereby enhancing the stability of the lithium extraction process, revealing a notable increase in electrode capacity retention from 79.04 % to 94.64 % after 30 cycles. Additionally, through DFT calculations and XPS analysis, the effectiveness of the manganese capture strategy is validated. This work presents an effective new strategy to extend the lifespan of manganese-based electrodes and enhance their adsorption performance.
Limin Liu,Yong Wang,Xiaoliang Zhou,Yixuan Yang,Chao Ma,Yuan Li,Chen Wang,Xiaohong Zhao,Bin Li
A cermet fuel electrode Cu/Ce 0.6 Mn 0.3 Fe 0.1 O 2-δ (Cu/CMF) is proposed for a reversible solid oxide electrochemical cell (SOC) with CO/CO 2 as the shuttle. Cu is inert for the carbon deposition and CMF is electrochemically active for CO oxidation and CO 2 reduction. The electrode polarization resistances in CO at 700, 750 and 800 °C are 0.328, 0.207 and 0.155 Ω cm 2 , respectively, presenting high electrochemical activity towards CO oxidation. The maximal power densities can reach up to 303.3, 482.2 and 691.9 mW/cm 2 at 700, 750 and 800 °C, respectively. When the reversible SOCs are operated in solid oxide electrolysis cell mode, the polarization resistance of the electrolysis cell for pure CO 2 reduction at 800 °C has the minimal value of 0.126 Ω cm 2 at 1.8 V. At 2.0 V, the current densities can reach up to 0.584 1.219 and 2.204 A/cm 2 at 700, 750 and 800 °C, respectively. The durability of the cell in CO for as long as 200 h indicates the electrode has remarkable stability. And the short-term stability characteristics for CO 2 electrolysis at different voltages illustrate that the cell performs well below 2.0 V. The harsh reducing environment at 2.0 V may be detrimental to the Cu/CMF electrode.