NIPS derived three-dimensional porous copper membrane for high-energy-density lithium-ion batteries

Increasing the capacity of electrode has attracted widespread attention for obtaining high energy density lithium-ion batteries. Here we report the controllable preparation strategy of three-dimensional porous Cu membrane to achieve this goal. Nonsolvent induce phase separation and heat treatment are synergistically used in the preparation of three-dimensional porous Cu membrane, which inherits the well developed three-dimensional channels and appropriate pore size (3–10 μm) from polymer architecture. The novel electrode, composing with three-dimensional porous Cu membrane and ball-milled graphite, exhibits a high initial reversible discharge specific gravimetric capacity of 858.4 mAhg−1 and volumetric capacity of 539.6 mAh cm−3, respectively. Meanwhile, the composite electrode shows a good rate capability (183.5 mAhg−1 at high rate of 2C) as well as a high reversible capacity of 660.2 mAh g−1 (415 mAh cm−3) with capacity retention of 76.9% after 150 cycles at 0.1C. The three-dimensional porous Cu membrane, acting as current collector, can not only load more nano-sized active material (4.4 mg cm−2), but also shorten the electron/ion transport paths, which may pave way to optimize the design of high energy density electrode for energy storage system.