Synthesis of Mesoporous Germanium Phosphide Microspheres for High-Performance Lithium-Ion and Sodium-Ion Battery Anodes

Abstract

Germanium phosphide is a potential anode material because of its high theoretical capacity and incredible rate capability on lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). However, the huge volume change that occurs while germanium phosphide is converted to Na3P or Li3P directly leads to poor cyclability and limits further applications. Herein, mesoporous germanium phosphide (MGeP x ) microspheres with diameter size ranging from 0.5 to 1.5 μm were first prepared by a one-step and template-free approach. MGeP x microspheres were composed of nanoparticles of around 10 nm with a narrow distribution of pore sizes of around 4 nm. The MGeP x possessed superior features in LIBs/SIBs since it shortens the diffusion path of the energy carrier and provides the buffer space for the transport of Li/Na ions. MGeP x showed attractive electrochemical properties as a potential anode candidate, such as a high first-cycle Coulombic efficiency of 82.63%, high reversible capacity (1400 mA h g–1 after 150 cycles at 0.2 C), excellent ultrahigh rate capacity (370 mA h g–1 at 72 A g–1, 40 C), and stable cycling performance (450 cycles at 1 C) in the LIBs and high reversible capacity (704 mA h g–1 after 100 cycles at 0.2 C) and stable cycling performance (200 cycles at 0.6 C) in SIBs.

Synthesis Strategies and Structural Design of Porous Carbon‐Incorporated Anodes for Sodium‐Ion Batteries

“…A graphene aerogel architecture was designed for the substrate for interconnection with the nanoparticles . Some other newly reported elements in metal phosphides, such as FeP, Sn 4 P 3 , CuP 2 , Se 3 P 4 , and GeP 5 also showed promising electrochemical properties with delicate structural designs and the participation of porous carbonaceous materials. It is reasonable to expect that more and more advanced synthesis strategies can be discovered and adopted for the improvement of metal phosphides in the near future.…”

Recent Advances and Optimization Strategies on the Electrolytes for Hard Carbon and P‐Based Sodium‐Ion Batteries

“…MPs has the advantages of low electrochemical reaction potential, high theoretical specific capacity and high volume energy density. Up to now, a large number of metal phosphides (such as FeP, [ 35,138 ] CuP 2 , [ 34 ] Cu 3 P, [ 123 ] Ni 2 P, [ 87 ] NiP 3 , [ 139 ] MoP, [ 140 ] CoP 3 , [ 118 ] Co 2 P, [ 119 ] CoP, [ 33,141 ] GeP 5 , [ 36 ] Sn 4 P 3 , [ 37 ] NiCoP, [ 38 ] MGeP x [ 142 ] ) have been used as anode materials for SIBs ( Figure ). The possible reasons for the dramatic capacity decay of MPs electrode in SIBs are that the MPs materials has a huge volume change and a stable SEI film does not form easily due to the constant corrosion of the SEI layers during the charging/discharging process by the organic electrolytes.…”

“…Many researchers have discussed that the low capacity retention rate of MPs materials due to formation of the SEI film can lead to irreversible electrolyte decomposition during the initial charge/discharge process, so the materials can show low ICE in SIBs. [ 36,123,124 ] However, due to the complex reactions taking place between MPs and sodium, some irreversible by‐products will be produced in the charge/discharge process of SIBs, which will cause significant changes in the material structure. The volume expansion of MPs material will also lead to the pulverization of MPs and the active material falling off from the current collector.…”

“…[ 27 ] For example, the excessive volume expansion (≈490%) during the charging and discharging process leads to serious pulverization of phosphorus, which intensifies the side reactions between the electrolyte and the electrode material and further leads to poor cycle stability of the battery. Numerous researchers have reported studies on the modification of phosphorus, such as coating (polydopamine layer or carbon layer), [ 19,28,29 ] compounding (carbon nanotube, TiP 2 , reduced graphene oxide, and so on), [ 19,30,31 ] metal‐doping (binary or ternary) [ 32–38 ] and so on. Although suitable architectural engineering on the P‐based anodes can deliver high specific capacity and good cycling performance, but it cannot fundamentally solve the problem of some side reactions between electrode materials and electrolyte.…”

N-doped hard/soft double-carbon-coated Na3V2(PO4)3 hybrid-porous microspheres with pseudocapacitive behaviour for ultrahigh power sodium-ion batteries

“…In the recent years, the development of high-energy and high-power density sodium-ion batteries (SIBs) is a great challenge for modern electrochemistry [4,5]. Recently, many spherical structure electrode materials, such as P 2 Na 0.7 CoO 2 microspheres [6], carbon-coated Na 2 MnPO 4 F hollow spheres [7], mesoporous germanium phosphide microspheres [8], hierarchical (Ni,Co)Se 2 /CNT hybrid microspheres [9], and so on, have been investigated for SIBs. Construction of these spherical materials has been demonstrated as an effective way to improve simultaneously the energy and power density, tap density, rate capability and cyclic stability of SIBs [10][11][12][13].…”