Highly Reversible Zn Metal Anodes Enabled by Increased Nucleation Overpotential

Dendrite formation severely compromises further development of zinc ion batteries. Increasing the nucleation overpotential plays a crucial role in achieving uniform deposition of metal ions. However, this strategy has not yet attracted enough attention from researchers to our knowledge. Here, we propose that thermodynamic nucleation overpotential of Zn deposition can be boosted through complexing agent and select sodium L-tartrate(Na-L) as example. Theoretical and experimental characterization reveals L-tartrate anion can partially replace H_(2)O in the solvation sheath of Zn^(2+), increasing de-solvation energy. Concurrently, the Na^(+) could absorb on the surface of Zn anode preferentially to inhibit the deposition of Zn^(2+) aggregation. In consequence, the overpotential of Zn deposition could increase from 32.2 to 45.1 mV with the help of Na-L. The Zn-Zn cell could achieve a Zn utilization rate of 80% at areal capacity of 20 mAh cm^(-2). Zn-LiMn_(2)O_(4) full cell with Na-L additive delivers improved stability than that with blank electrolyte. This study also provides insight into the regulation of nucleation overpotential to achieve homogeneous Zn deposition.

Water-facilitated targeted repair of degraded cathodes for sustainable lithium-ion batteries

Directly repairing end-of-life lithium-ion battery cathodes poses significant chal-lenges due to the diverse compositions of the wastes.Here,we propose a water-facilitated targeted repair strategy applicable to various end-of-life batches and cathodes.The process involves initiating structural repair and reconstruct-ing particle morphology in degraded LiMn_(2)O_(4)(LMO)through an additional thermal drive post-ambient water remanganization,achieving elemental repair.Compared to solid-phase repair,the resulting LMO material exhibits superior electrochemical and kinetic characteristics.The theoretical analysis highlights the impact of Mn defects on the structural stability and electron transfer rate of degraded materials.The propensity of Mn ions to diffuse within the Mn layer,specifically occupying the Mn 16d site instead of the Li 8a site,theoretically sup-ports the feasibility of ambient water remanganization.Moreover,this method proves effective in the relithiation of degraded layered cathode materials,yielding single crystals.By combining low energy consumption,environmental friendli-ness,and recyclability,our study proposes a sustainable approach to utilizing spent batteries.This strategy holds the potential to enable the industrial direct repair of deteriorated cathode materials.