Developing anodes with a high and stable energy density for both gravimetric and volumetric storage is vital for high-performance lithium/sodium-ion batteries. Herein, an SnSe/few-layered graphene (FLG) composite with a high tap density (2.3 g cm −3 ) is synthesized via the plasma-milling method, in which SnSe nanoparticles are strongly bound with the FLG matrix, owing to both Sn−C and Se−C bonds, to form nanosized primary particles and then assemble to microsized secondary granules. The FLG can effectively alleviate the large stress generated from the volume expansion of SnSe during cycling based on its superstrength. Furthermore, as demonstrated by the density-functional theory calculations, the Sn−C and Se−C co-bonding benefitting from the formation of substantial vacancy defects on the P-milling-synthesized FLG enables strong affinity between SnSe nanoparticles and the FLG matrix, preventing SnSe from aggregating and detaching even after long-term cycling. As an anode for lithium-ion batteries, it exhibits high gravimetric and volumetric capacities (864.8 mAh g −1 and 1990 mAh cm −3 at 0.2 A g −1 ), a high rate (612.6 mAh g −1 even at 5.0 A g −1 ), and the longest life among the reported SnSe-based anodes (capacity retention of 92.8% after 2000 cycles at 1.0 A g −1 ). Subsequently, an impressive cyclic life (capacity retention of 91.6% after 1000 cycles at 1.0 A g −1 ) is also achieved for sodium-ion batteries. Therefore, the SnSe/FLG composite is a promising anode for high-performance lithium/sodium-ion batteries.

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The nano-spatially confined and interface-controlled lithiation/delithiation endows an in situ formed (SnS–SnS2–S)/FLG composite with ultrafast and ultrastable lithium storage.

SnS with high theoretical capacity is a promising anode material for lithium‐ion batteries. However, dramatic volume changes of SnS during repeated discharge/charge cycles result in fractures or even pulverization of electrode, leading to rapid capacity degradation. To solve this problem, we construct a dual‐carbon‐confined SnS nanostructure (denoted as SnS@C/rGO) by depositing semi‐graphitized carbon layers on reduced graphene oxide (rGO) supported SnS nanoplates during high‐temperature reduction. The dual carbon of rGO and in situ formed carbon coating confines growth of SnS during the high‐temperature calcination. Moreover, during the reversible Li+ storage the dual‐carbon modification enables good electronic conductivity, relieves the volume effect, and provides double insurance for the electrical contact of SnS even after repeated cycles. Benefiting from the dual‐carbon confinement, SnS@C/rGO exhibits significantly enhanced rate capability and cycling stability compared with the bare and single carbon modified SnS. SnS@C/rGO presents reversible capacity of 1029.8 mAh g−1 at 0.2 A g−1. Even at a high current density of 1 A g−1, it initially delivers reversible capacity of 934.0 mAh g−1 and retains 98.2% of the capacity (918.0 mAh g−1) after 330 cycles. This work demonstrates potential application of dual‐carbon modification in the development of electrode materials for high‐performance lithium‐ion batteries.