▎ 摘　　要

Metal oxalate has become a most promising candidate as an anode material for lithium-ion and sodium-ion batteries. However, capacity decrease owing to the volume expansion of the active material during cycling is a problem. Herein, a rod-like CoC2O4.2 H2O/rGO hybrid is fabricated through a novel multistep solvo/hydrothermal strategy. The structural characteristics of the CoC2O4.2 H2O microrod wrapped using rGO sheets not only inhibit the volume variation of the hybrid electrode during cycling, but also accelerate the transfer of electrons and ions in the 3 D graphene network, thereby improving the electrochemical properties of CoC2O4.2 H2O. The CoC2O4.2 H2O/rGO electrode delivers a specific capacity of 1011.5 mA h g(-1) at 0.2 A g(-1) after 200 cycles for lithium storage, and a high capacity of 221.1 mA h g(-1) at 0.2 A g(-1) after 100 cycles for sodium storage. Moreover, the full cell CoC2O4.2 H2O/rGO//LiCoO2 consisting of the CoC2O4.2 H2O/rGO anode and LiCoO2 cathode maintains 138.1 mA h g(-1) after 200 cycles at 0.2 A g(-1) and has superior long-cycle stability. In addition, in situ Raman spectroscopy and in situ and ex situ X-ray diffraction techniques provide a unique opportunity to understand fully the reaction mechanism of CoC2O4.2 H2O/rGO. This work also gives a new perspective and solid research basis for the application of metal oxalate materials in high-performance lithium-ion and sodium-ion batteries.