HIGH COULOMBIC EFFICIENCY CYCLING OF METAL BATTERIES

摘要

Embodiments of a method for cycling a rechargeable alkali metal battery with high Coulombic efficiency (CE) are disclosed. A slow charge/rapid discharge protocol is used in conjunction with a concentrated electrolyte to achieve high CE in rechargeable lithium and sodium batteries, include anode-free batteries. In some examples, the CE is ≧99.8%.

主权项

1. A method for cycling a rechargeable alkali metal battery, comprising:
charging a rechargeable alkali metal battery at a first current density C1, wherein the rechargeable alkali metal battery prior to an initial charge cycle comprises
(i) a cathode comprising M+, where M is an alkali metal,(ii) an anode current collector and no anode, or an anode current collector in physical contact with a thin layer of M having an average thickness from 1 μm to 20 μm,(iii) a separator disposed between the anode current collector and the cathode, and(iv) an electrolyte comprising a salt comprising M+ dissolved in a non-aqueous solvent, the electrolyte having a concentration of M+ within a range of 2 M to 8 M; and discharging the rechargeable alkali metal battery at a second current density C2, wherein C2 ≧2×C1.