Conquering Corrosion of Aluminum Current Collector in Commercial Lithium-Ion Battery Via 2D Conductive Nanosheets Assembled films

摘要

Elevating operating voltage is a consequential approach to increasing the energy density of lithium -ion batteries (LIBs). Unfortunately, the corrosion of cathode aluminum (Al) current collector at high voltage limits the application of high -voltage LIBs. And this report describes the corrosion inhibition on the Al current collector in commercial LiPF6-ester electrolyte (LB-092) by constructing conductive barrier layers. MXene-Ti3C2Tx nanosheets are proposed as an armored layer for Al. The Ti3C2Tx layer is fabricated via a self-assembly procedure, which exhibits ultra-thinness less than 100 nm, attaches to Al substrate homogeneously, and ensures the electron conduction by virtue of outstanding conductivity. Ti3C2Tx-Al can comprehensively enhance the cyclic and rate performance of Li|NMC333 battery at a cut-off voltage of 4.5 V and delay the trend of self-discharge. However, the preparation and storage of Ti3C2Tx-Al rely on an inert argon atmosphere in a glove box. To further enhance the industrial feasibility, MXene-Mo2CTx with greater chemical stability is firmly deposited on the Al surface through electrophoretic deposition. And t o broaden the electrochemical stability of Mo2CTx-Al, a mild tactic of potentiostatic polarization is applied to tailor Mo 2CTx terminal at around 5.3 V vs. Li/Li + for 60 s. After electrochemical tailoring, t he -F terminal ratio is significantly increased. The obtained Mo 2CFx-Al exhibits uniform electrical conductivity similar to bare Al and outstanding antioxidation over 5 V vs. Li/Li+. As a consequence, Li|NMC333 using Mo 2CFx-Al demonstrate s superior electrochemical performance at a higher cut -off voltage of 4.6 V. The discharge capacity retention is increased from 7.0% to 62.3% after 500 cycles at 0.5 C. And the rate performance at 3 C is also improved by about 300 %. This report contributes to the surface engineering and application of MXene nanosheets, as well as provides an effective strategy for developing stable high-voltage LIBs.