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Thanks to the attractive structural characteristics and unique physicochemical properties, mixed metal selenides (MMSes) can be considered as encouraging electrode materials for energy storage devices. Herein, a straightforward and efficient approach is used to construct multi-shelled nickel–manganese selenide hollow spheres (MSNMSeHSs) as cathode and double-shell nickel–iron selenide hollow spheres (DSNFSeHSs) as anode electrode materials by tuning shell numbers for supercapacitors. The as-designed MSNMSeHS electrode can deliver a splendid capacity of ∼339.2 mA h g−1/1221.1 C g−1, impressive rate performances of 78.8%, and considerable longevity of 95.7%. The considerable performance is also observed for the DSNFSeHS electrode with a capacity of 258.4 mA h g−1/930.25 C g−1, rate performance of 75.5%, and longevity of 90.9%. An efficient asymmetric apparatus (MSNMSeHS …