Constructing Self-Protected Li and Non-Li Candidates for Advanced Lithium Ion and Lithium Metal Batteries

Poly(vinylidene fluoride-co-hexafluoropropylene) and Li7La3Zr2O12-poly(vinylidene fluoride-co-hexafluoropropylene) films were introduced to both Li and non-Li anodes. Via the recombination of poly(vinylidene fluoride-co-hexafluoropropylene)-Li7La3Zr2O12, the ionic conductivity of the anodes has been greatly improved, and the deposition/plating barrier has been decreased. On the one hand, the thin film introduced upon lithium metal ensures cyclic stability in both symmetrical cells and full cells. The Li metal with Li7La3Zr2O12-poly(vinylidene fluoride-co-hexafluoropropylene) films behaved stably over 500 h with little increase in polarization. On the other hand, the modification upon Cu foil provided a long cycle life over 300 cycles in Li–Cu cells. When the poly(vinylidene fluoride-co-hexafluoropropylene)-Li7La3Zr2O12@Cu foil (non-Li anode) failed, a type of self-protected mechanism was activated, ensuring better mechanical properties and safety.