Polymer-Based Strategies for High-Energy-Density Lithium Batteries

There are various strategies to increase the energy density of rechargeable batteries including the fabrication of high-areal-capacity electrode, Li metal batteries, and anode-free batteries. First, I introduce a covalently interconnected system employing silicon microparticles and a highly elastic gel polymer electrolyte. Through the cost-effective but practical approach of electron beam technology, the resulting 500 mAh-pouch cell showed exceptional stability and high gravimetric/volumetric energy densities of 413 Wh/kg, 1022 Wh/L, highlighting the feasibility even in current battery production lines. As the second topic, Li metal anode emerges as a promising candidate for Li-based battery chemistry with high-energy-density. I introduce an innovative Li metal anode model deploying a hyperporous/hybrid conductive architecture on single-walled carbon nanotube film, fabricated through a nonsolvent induced phase separation process. This design integrates ionic polymers with conductive carbon, offering a substantial improvement over traditional metal current collectors by reducing the weight of Li metal anode and enabling high-energy-density batteries (951 Wh/L based on the total mass of the cell). Third, anode-free Li metal batteries are one of the finest prospects for increasing energy density beyond that of standard lithium-ion batteries. Conversely, the absence of Li reservoir generates unwarranted volume expansion, permitting electrolyte depletion and rapid cathode capacity consumption. To address this issue, I introduce an anode-free Li metal battery with an ion-conductive layer coated Cu current collector in typical carbonate-based electrolytes. Stacked pouch-type full cells further deliver a record volumetric energy density of 1270 Wh/L (including packaging) under lean electrolyte and low stack pressure (~20 kPa). This synergistic approach delineates a practical pathway toward high-energy, long-life anode-free LMBs for advanced energy storage systems.