Tailoring multi-layer architectured FeS2@C hybrids for superior sodium-, potassium- and aluminum-ion storage

The development of new rechargeable metal-ion (Na+, K+ or Al3+) batteries (MIBs) with high performance would break the global monopoly on lithium-ion batteries (LIBs). However, because of the larger ionic sizes of Na+, K+ and Al3+ in comparison to Li+, the requirement of electrode materials with suitable tunnels for these metal ions insertion/extraction is more stringent. Over years, a large number of electrodes materials are studied and optimized for a specific type of MIB, yet a universal suitable candidate that can be applied for all of them still remains scarce. Here we report a solvothermal method coupled with the sulfidation strategy to engineer novel multi-layer architecture of FeS2@C hybrids which is constructed from building blocks of ultrathin nanoflakes, favoring fast electrochemical energy storage. Electrochemical measurements show that the multi-layer structured FeS2@C hybrids enables reversible sodium-, potassium- and aluminum-ion storage process with high specific capacities, excellent rate capability and outstanding cycling stability. We hope that this research will inspire new ideas for developing various electrode materials for high-performance MIBs.