Gallium Sulfide–Single‐Walled Carbon Nanotube Composites: High‐Performance Anodes for Lithium‐Ion Batteries

Metal sulfides are an important class of functional materials possessing exceptional electrochemical performance and thus hold great promise for rechargeable secondary batteries. In this work, we deposited gallium sulfide (GaS_x, x = 1.2) thin films by atomic layer deposition (ALD) onto single‐walled carbon nanotube (SWCNT) powders. The ALD GaS_x was performed at 150 °C, and produced uniform and conformal amorphous films. The resulting core‐shell, nanostructured SWCNT‐GaS_x composite exhibited excellent electrochemical performance as an anode material for lithium‐ion batteries (LIBs), yielding a stable capacity of ≈575 mA g^–1 at a current density of 120 mA g^–1 in the voltage window of 0.01–2 V, and an exceptional columbic efficiency of >99.7%. The GaS_x component of the composite produced a specific capacity of 766 mA g^–1, a value two times that of conventional graphite anodes. We attribute the excellent electrochemical performance of the composite to four synergistic effects: 1) the uniform and conformal ALD GaS_x coating offers short electronic and Li‐ion pathways during cycling; 2) the amorphous structure of the ALD GaS_x accommodates stress during lithiation‐delithiation processes; 3) the mechanically robust SWCNT framework also accommodates stress from cycling; 4) the SWCNT matrix provides a continuous, high conductivity network.     

Unraveling the Formation of Amorphous MoS2 Nanograins during the Electrochemical Delithiation Process

Molybdenum disulfide (MoS₂) is a promising high‐capacity anode for lithium‐ion batteries. However, the conversion reaction mechanism of MoS₂ (the delithiation pathway in particular) has been controversial, which limits the rational optimization of its electrochemical performance. The main challenge is how to precisely identify the amorphous nanomaterials generated during lithiation/delithiation. Here, the structural evolutions of MoS₂ during lithiation/delithiation are systematically investigated using synchrotron X‐ray absorption spectroscopy at Mo K‐edge and S K‐edge and Raman spectroscopy. It is revealed that amorphous MoS₂ nanograins rather than sulfur as previously suggested, are formed after delithiation, and that the fully lithiated MoS₂ electrode contains additional Mo‐S related phases besides the known Mo and Li₂S. Density functional theory simulations suggest that the Mo nanoparticles formed during lithiation are very reactive with Li₂S, thus enabling the regeneration of MoS₂ upon delithiation. These findings deepen the understanding of the lithiation/delithiation mechanism of MoS₂, which will pave the way for the rational design of advanced MoS₂‐based electrodes.     

Inserting Sn Nanoparticles into the Pores of TiO2−x–C Nanofibers by Lithiation

Tin holds promise as an anode material for lithium‐ion batteries (LIBs) because of its high theoretical capacity, but its cycle life is limited by structural degradation. Herein, a novel approach is exploited to insert Sn nanoparticles into the pores of highly stable titanium dioxide–carbon (TiO_2?x–C) nanofiber substrates that can effectively localize the postformed smaller Sn nanoparticles, thereby address the problem of structural degradation, and thus achieve improved anode performance. During first lithiation, a Li_4.4Sn alloy is inserted into the pores surrounding the initial Sn nanoparticles in TiO_2?x–C nanofibers by its large volume expansion. Thereafter, the original Sn nanoparticle with a diameter of about 150 nm cannot be recovered by the delithiation because of the surface absorption between inserted Sn nanoparticles and the TiO_2?x–C substrate, resulting in many smaller Sn nanoparticles remaining in the pores. Batteries containing these porous TiO_2?x–C–Sn nanofibers exhibit a high capacity of 957 mAh g^?1 after 200 cycles at 0.1 A g^?1 and can cycle over 10 000 times at 3 A g^?1 while retaining 82.3% of their capacity, which represents the longest cycling life of Sn‐based anodes for LIBs so far. This interesting method can provide new avenues for other high‐capacity anode material systems that suffer from significant volume expansion.     

Carbon‐Nanotube‐Cored Cobalt Porphyrin as a 1D Nanohybrid Strategy for High‐Performance Lithium‐Ion Battery Anodes

Redox‐active organic electrode materials have garnered considerable interest as an emerging alternative to currently widespread inorganic‐(or metal)‐based counterparts in lithium‐ion batteries (LIBs). Practical use of these materials, however, has posed a challenge due to their electrically insulating nature, limited specific capacity, and poor electrochemical durability. Here, a new class of multiwalled‐carbon‐nanotube‐(MWCNT)‐cored, meso‐tetrakis(4‐carboxyphenyl)porphyrinato cobalt (CoTCPP) is demonstrated as a 1D nanohybrid (denoted as CC‐nanohybrid) strategy to develop an advanced LIB anode. CoTCPP, which is one of the metalloporphyrins having multielectron redox activities, shows strong noncovalent interactions with MWCNTs due to its conjugated π‐bonds, resulting in successful formation of the CC‐nanohybrids. The structural uniqueness of the CC‐nanohybrid facilitates electron transport and electrolyte accessibility, thereby improving their redox kinetics. Inspired by the 1D structure of the CC‐nanohybrid, all‐fibrous nanomat anode sheets are fabricated through concurrent electrospraying/electrospinning processes. The resulting nanomat anode sheets, driven by their 3D bicontinuous ion/electron conduction pathways, provide fast lithiation/delithiation kinetics, eventually realizing the well‐distinguishable lithiation behavior of CoTCPP. Notably, the nanomat anode sheets exhibit exceptional electrochemical performance (≈226 mAh g_sheet ^?1 and >1500 cycles at 5 C) and mechanical flexibility that lie far beyond those achievable with conventional LIB anode technologies.     

Core–Shelled Low‐Oxidation State Oxides@Reduced Graphene Oxides Cubes via Pressurized Reduction for Highly Stable Lithium Ion Storage

Metal oxides have been regarded as promising next‐generation anode materials for rechargeable lithium ion batteries; however, their poor stability, which is caused by large volume changes during repeated lithiation/delithiation, remains a challenge. Here, conformally encapsulated low‐oxidation state oxide cubes with reduced graphene oxide (RGO) obtained via a new pressurized reduction consisting of external mechanical compression and internal thermokinetic reduction from highly porous metal oxides/RGO aerogel (RGOA) are reported. Using single crystalline (SC) cobalt oxides and iron oxide cubes as model systems, the SC‐Co₃O₄ or Fe₂O₃ cube/RGOA are pressurized into compacted xerogel along with a uniform thermokinetic reduction, which result in topotactic transformation to core‐shelled CoO/RGO or Fe₃O₄@RGO cubes. The SC‐CoO and SC‐Fe₃O₄ cubes isolated perfectly in the RGO shells have dramatically improved their cycling stabilities for lithium ion storage to hundreds of times.     

Reconstruction of Conformal Nanoscale MnO on Graphene as a High‐Capacity and Long‐Life Anode Material for Lithium Ion Batteries

To tackle the issue of inferior cycle stability and rate capability for MnO anode materials in lithium ion batteries, a facile strategy is explored to prepare a hybrid material consisting of MnO nanocrystals grown on conductive graphene nanosheets. The prepared MnO/graphene hybrid anode exhibits a reversible capacity as high as 2014.1 mAh g^?1 after 150 discharge/charge cycles at 200 mA g^?1, excellent rate capability (625.8 mAh g^?1 at 3000 mA g^?1), and superior cyclability (843.3 mAh g^?1 even after 400 discharge/charge cycles at 2000 mA g^?1 with only 0.01% capacity loss per cycle). The results suggest that the reconstruction of the MnO/graphene electrodes is intrinsic due to conversion reactions. A long‐term stable nanoarchitecture of graphene‐supported ultrafine manganese oxide nanoparticles is formed upon cycling, which yields a long‐life anode material for lithium ion batteries. The lithiation and delithiation behavior suggests that the further oxidation of Mn(II ) to Mn(IV ) and the interfacial lithium storage upon cycling contribute to the enhanced specific capacity. The excellent rate capability benefits from the presence of conductive graphene and a short transportation length for both lithium ions and electrons. Moreover, the as‐formed hybrid nanostructure of MnO on graphene may help achieve faster kinetics of conversion reactions.     

Metal–Organic Framework (MOF) Derived Electrodes with Robust and Fast Lithium Storage for Li‐Ion Hybrid Capacitors

Hybrid metal–organic frameworks (MOFs) demonstrate great promise as ideal electrode materials for energy‐related applications. Herein, a well‐organized interleaved composite of graphene‐like nanosheets embedded with MnO₂ nanoparticles (MnO₂@C‐NS) using a manganese‐based MOF and employed as a promising anode material for Li‐ion hybrid capacitor (LIHC) is engineered. This unique hybrid architecture shows intriguing electrochemical properties including high reversible specific capacity 1054 mAh g^?1 (close to the theoretical capacity of MnO₂, 1232 mAh g^?1) at 0.1 A g^?1 with remarkable rate capability and cyclic stability (90% over 1000 cycles). Such a remarkable performance may be assigned to the hierarchical porous ultrathin carbon nanosheets and tightly attached MnO₂ nanoparticles, which provide structural stability and low contact resistance during repetitive lithiation/delithiation processes. Moreover, a novel LIHC is assembled using a MnO₂@C‐NS anode and MOF derived ultrathin nanoporous carbon nanosheets (derived from other potassium‐based MOFs) cathode materials. The LIHC full‐cell delivers an ultrahigh specific energy of 166 Wh kg^?1 at 550 W kg^?1 and maintained to 49.2 Wh kg^?1 even at high specific power of 3.5 kW kg^?1 as well as long cycling stability (91% over 5000 cycles). This work opens new opportunities for designing advanced MOF derived electrodes for next‐generation energy storage devices.     

Walnut‐Like Multicore–Shell MnO Encapsulated Nitrogen‐Rich Carbon Nanocapsules as Anode Material for Long‐Cycling and Soft‐Packed Lithium‐Ion Batteries

Metal oxide‐based nanomaterials are widely studied because of their high‐energy densities as anode materials in lithium‐ion batteries. However, the fast capacity degradation resulting from the large volume expansion upon lithiation hinders their practical application. In this work, the preparation of walnut‐like multicore–shell MnO encapsulated nitrogen‐rich carbon nanocapsules (MnO@NC) is reported via a facile and eco‐friendly process for long‐cycling Li‐ion batteries. In this hybrid structure, MnO nanoparticles are uniformly dispersed inside carbon nanoshells, which can simultaneously act as a conductive framework and also a protective buffer layer to restrain the volume variation. The MnO@NC nanocapsules show remarkable electrochemical performances for lithium‐ion batteries, exhibiting high reversible capability (762 mAh g^?1 at 100 mA g^?1) and stable cycling life (624 mAh g^?1 after 1000 cycles at 1000 mA g^?1). In addition, the soft‐packed full batteries based on MnO@NC nanocapsules anodes and commercial LiFePO₄ cathodes present good flexibility and cycling stability.     

Zn(Cu)Si2+xP3 Solid Solution Anodes for High‐Performance Li‐Ion Batteries with Tunable Working Potentials

Si‐based anodes with a stiff diamond structure usually suffer from sluggish lithiation/delithiation reaction due to low Li‐ion and electronic conductivity. Here, a novel ternary compound ZnSi₂P₃ with a cation‐disordered sphalerite structure, prepared by a facile mechanochemical method, is reported, demonstrating faster Li‐ion and electron transport and greater tolerance to volume change during cycling than the existing Si‐based anodes. A composite electrode consisting of ZnSi₂P₃ and carbon achieves a high initial Coulombic efficiency (92%) and excellent rate capability (950 mAh g^?1 at 10 A g^?1) while maintaining superior cycling stability (1955 mAh g^?1 after 500 cycles at 300 mA g^?1), surpassing the performance of most Si‐ and P‐based anodes ever reported. The remarkable electrochemical performance is attributed to the sphalerite structure that allows fast ion and electron transport and the reversible Li‐storage mechanism involving intercalation and conversion reactions. Moreover, the cation‐disordered sphalerite structure is flexible to ionic substitutions, allowing extension to a family of Zn(Cu)Si_2+xP₃ solid solution anodes (x = 0, 2, 5, 10) with large capacity, high initial Coulombic efficiency, and tunable working potentials, representing attractive anode candidates for next‐generation, high‐performance, and low‐cost Li‐ion batteries.     

Two Birds with One Stone: Metal–Organic Framework Derived Micro‐/Nanostructured Ni2P/Ni Hybrids Embedded in Porous Carbon for Electrocatalysis and Energy Storage

The construction of bifunctional electrode materials for hydrogen evolution reaction (HER) and lithium‐ion batteries (LIBs) has been a hot topic of research. Herein, metal–organic frameworks (MOFs) derived micro‐/nanostructured Ni₂P/Ni hybrids with a porous carbon coating (denoted as Ni₂P/Ni@C) are prepared using a feasible pyrolysis–phosphidation strategy. On the one hand, the optimal Ni₂P/Ni@C catalyst exhibits superior HER performance with a low overpotential of 149 mV versus a reversible hydrogen electrode (RHE) at 10 mA cm^?2 and excellent durability. The density functional theory computations verify that the strong synergistic effect between Ni₂P and Ni could optimize the electronic structure, thus rendering the enhanced electrocatalytic performance. On the other hand, the Ni₂P/Ni@C electrode displays a reversible capacity of 597 mAh g^?1 after 1000 cycles at 1000 mA g^?1 and improved rate capability as an anode for LIBs, owing to the well‐organized micro‐/nanostructure and conductive Ni core. In addition, the electrochemical reaction mechanism of the Ni₂P/Ni@C electrode upon lithiation/delithiation is investigated in detail via ex situ X‐ray powder diffraction and X‐ray photoelectron spectroscopy methods. It is expected that the facile and controllable approach can be extended to fabricate other MOF‐based metal phosphides/metal hybrids for electrochemical energy storage and conversion systems.     

A High‐Energy Aqueous Aluminum‐Manganese Battery

Rechargeable aluminum‐ion batteries have drawn considerable attention as a new energy storage system, but their applications are still significantly impeded by critical issues such as low energy density and the lack of excellent electrolytes. Herein, a high‐energy aluminum‐manganese battery is fabricated by using a Birnessite MnO₂ cathode, which can be greatly optimized by a divalence manganese ions (Mn²⁺) electrolyte pre‐addition strategy. The battery exhibits a remarkable energy density of 620 Wh kg^?1 (based on the Birnessite MnO₂ material) and a capacity retention above 320 mAh g^?1 for over 65 cycles, much superior to that with no Mn²⁺ pre‐addition. The electrochemical reactions of the battery are scrutinized by a series of analysis techniques, indicating that the Birnessite MnO₂ pristine cathode is first reduced as Mn²⁺ to dissolve in the electrolyte upon discharge, and Al_xMn_(1?x)O₂ is then generated upon charge, serving as a reversible cathode active material in following cycles. This work provides new opportunities for the development of high‐performance and low‐cost aqueous aluminum‐ion batteries for prospective applications.     

Reversible and High‐Capacity Nanostructured Electrode Materials for Li‐Ion Batteries

Reversible nanostructured electrode materials are at the center of research relating to rechargeable lithium batteries, which require high power, high capacity, and high safety. The higher capacities and higher rate capabilities for the nanostructured electrode materials than for the bulk counterparts can be attributed to the higher surface area, which reduces the overpotential and allows faster reaction kinetics at the electrode surface. These electrochemical enhancements can lead to versatile potential applications of the batteries and can provide breakthroughs for the currently limited power suppliers of mobile electronics. This Feature Article describes recent research advances on nanostructured cathode and anode materials, such as metals, metal oxides, metal phosphides and LiCoO₂, LiNi_1–xM_xO₂ with zero‐, one‐, two‐, and three‐dimensional morphologies.     

Overcoming the Unfavorable Kinetics of Na3V2(PO4)2F3//SnPx Full‐Cell Sodium‐Ion Batteries for High Specific Energy and Energy Efficiency

In this work, a full‐cell sodium‐ion battery (SIB) with a high specific energy approaching 300 Wh kg^?1 is realized using a sodium vanadium fluorophosphate (Na₃V₂(PO₄)₂F₃, NVPF) cathode and a tin phosphide (SnP_x) anode, despite both electrode materials having greatly unbalanced specific capacities. The use of a cathode employing an areal loading more than eight times larger than that of the anode can be achieved by designing a nanostructured nanosized NVPF (n‐NVPF) cathode with well‐defined particle size, porosity, and conductivity. Furthermore, the high rate capability and high potential window of the full‐cell can be obtained by tuning the Sn/P ratio (4/3, 1/1, and 1/2) and the nanostructure of an SnP_x/carbon composite anode. As a result, the full‐cell SIBs employing the nanostructured n‐NVPF cathode and the SnP_x/carbon composite anode (Sn/P = 1/1) exhibit outstanding specific energy (≈280 Wh kg^?1_{(cathode+anode)}) and energy efficiency (≈78%); furthermore, the results are comparable to those of state‐of‐the‐art lithium‐ion batteries.     

Hierarchical Defective Fe3‐xC@C Hollow Microsphere Enables Fast and Long‐Lasting Lithium–Sulfur Batteries

Lithium–sulfur (Li–S) batteries present one of the most promising energy storage systems owing to their high energy density and low cost. However, the commercialization of Li–S batteries is still hindered by several technical issues; the notorious polysulfide shuttling and sluggish sulfur conversion kinetics. In this work, unique hierarchical Fe_3‐xC@C hollow microspheres as an advanced sulfur immobilizer and promoter for enabling high‐efficiency Li–S batteries is developed. The porous hollow architecture not only accommodates the volume variation upon the lithiation–delithiation processes, but also exposes vast active interfaces for facilitated sulfur redox reactions. Meanwhile, the mesoporous carbon coating establishes a highly conductive network for fast electron transportation. More importantly, the defective Fe_3‐xC nanosized subunits impose strong LiPS adsorption and catalyzation, enabling fast and durable sulfur electrochemistry. Attributed to these structural superiorities, the obtained sulfur electrodes exhibit excellent electrochemical performance, i.e., high areal capacity of 5.6 mAh cm^?2, rate capability up to 5 C, and stable cycling over 1000 cycles with a low capacity fading rate of 0.04% per cycle at 1 C, demonstrating great promise in the development of practical Li–S batteries.     

Lithium Ion Breathable Electrodes with 3D Hierarchical Architecture for Ultrastable and High‐Capacity Lithium Storage

Transition‐metal oxides show genuine potential in replacing state‐of‐the‐art carbonaceous anode materials in lithium‐ or sodium‐ion batteries because of their much higher theoretical capacity. However, they usually undergo massive volume change, which leads to numerous problems in both material and electrode levels, such as material pulverization, instable solid‐electrolyte interphase, and electrode failure. Here, it is demonstrated that lithium‐ion breathable hybrid electrodes with 3D architecture tackle all these problems, using a typical conversion‐type transition‐metal oxide, Fe₃O₄, of which nanoparticles are anchored onto 3D current collectors of Ni nanotube arrays (NTAs) and encapsulated by δ‐MnO₂ layers (Ni/Fe₃O₄@MnO₂). The δ‐MnO₂ layers reversibly switch lithium insertion/extraction of internal Fe₃O₄ nanoparticles and protect them against pulverizing and detaching from NTA current collectors, securing exceptional integrity retention and efficient ion/electron transport. The Ni/Fe₃O₄@MnO₂ electrodes exhibit superior cyclability and high‐capacity lithium storage (retaining ≈1450 mAh g^?1, ≈96% of initial value at 1 C rate after 1000 cycles).     

Ultrafine Nickel‐Nanoparticle‐Enabled SiO2 Hierarchical Hollow Spheres for High‐Performance Lithium Storage

The high theoretical capacity and natural abundance of SiO₂ make it a promising high‐capacity anode material for lithium‐ion batteries. However, its widespread application is significantly hampered by the intrinsic poor electronic conductivity and drastic volume variation. Herein, a unique hollow structured Ni/SiO₂ nanocomposite constructed by ultrafine Ni nanoparticle (≈3 nm) functionalized SiO₂ nanosheets is designed. The Ni nanoparticles boost not only the electronic conductivity but also the electrochemical activity of SiO₂ effectively. Meanwhile, the hollow cavity provides sufficient free space to accommodate the volume change of SiO₂ during repeated lithiation/delithiation; the nanosheet building blocks reduce the diffusion lengths of lithium ions. Due to the synergistic effect between Ni and SiO₂, the Ni/SiO₂ composite delivers a high reversible capacity of 676 mA h g^?1 at 0.1 A g^?1. At a high current density of 10 A g^?1, a capacity of 337 mA h g^?1 can be retained after 1000 cycles.     

Discovering a Dual‐Buffer Effect for Lithium Storage: Durable Nanostructured Ordered Mesoporous Co–Sn Intermetallic Electrodes

Lithiation–delithiation reactions in Li‐ion batteries do exhibit a huge electrochemically driven volume change of the anode material between the lithium‐free and lithiated‐host states, which results in a gradually fading capacity. Minimizing this volume change of the electrode during cycling is essential to achieve stable electrochemical behavior and thus for innovating design of electrode materials for Li storage. Here, ordered mesoporous CoSn intermetallic anode materials with various Co/Sn atomic ratios are developed. A dual‐buffer effect is discovered that accommodates the volume changes in the electrode material by not only repeatedly generating void nanospaces but also by incorporating electrochemically inactive elements. Novel insights into the nanostructural changes of electrode materials during the lithiation–delithiation process are obtained by in operando small angle X‐ray scattering. The degrees of volume change and nanoscopic order are found to be highly dependent on the Co contents in the mesoporous CoSn intermetallic anode materials, being possible to achieve a durable nanostructured electrode upon prolonged cycling.     

GeO2 Encapsulated Ge Nanostructure with Enhanced Lithium‐Storage Properties

Germanium (Ge)‐based nanostructures, especially those with germanium dioxide (GeO₂), have drawn great interest for applications in lithium (Li)‐ion batteries due to their ultrahigh theoretical Li⁺ storage capability (8.4 Li/Ge). However, GeO₂ in conventional Ge(s)/GeO₂(c) (where (c) means the core and (s) means the shell) composite anodes with Ge shell outside GeO₂ undergoes an irreversible conversion reaction, which restricts the maximum capacity of such batteries to 1126 mAhg^?1 (the equivalent of storing 4.4 Li⁺). In this work, a porous GeO₂(s)/Ge(c) nanostructure with GeO₂ shell outside Ge cores are successfully fabricated utilizing the Kirkendall effect and used as a lithium‐ion battery anode, giving a substantially improved capacity of 1333.5 mAhg^?1 at a current density of 0.1 Ag^?1 after 30 cycles and a stable long‐time cycle performance after 100 cycles at a current density of 0.5 A g^?1. The enhanced battery performance is attributed to the improved reversibility of GeO₂ lithiation/delithiation processes catalyzed by Ge in the properly structured porous GeO₂(s)/Ge(c) nanostructure.     

Enhanced Interfacial Stability of Hybrid‐Electrolyte Lithium‐Sulfur Batteries with a Layer of Multifunctional Polymer with Intrinsic Nanoporosity

The use of lithium‐ion conductive solid electrolytes offers a promising approach to address the polysulfide shuttle and the lithium‐dendrite problems in lithium‐sulfur (Li‐S) batteries. One critical issue with the development of solid‐electrolyte Li‐S batteries is the electrode–electrolyte interfaces. Herein, a strategic approach is presented by employing a thin layer of a polymer with intrinsic nanoporosity (PIN) on a Li⁺‐ion conductive solid electrolyte, which significantly enhances the ionic interfaces between the electrodes and the solid electrolyte. Among the various types of Li⁺‐ion solid electrolytes, NASICON‐type Li_1+xAl_xTi_2‐x(PO₄)₃ (LATP) offers advantages in terms of Li⁺‐ion conductivity, stability in ambient environment, and practical viability. However, LATP is susceptible to reaction with both the Li‐metal anode and polysulfides in Li‐S batteries due to the presence of easily reducible Ti⁴⁺ ions in it. The coating with a thin layer of PIN presented in this study overcomes the above issues. At the negative‐electrode side, the PIN layer prevents the direct contact of Li‐metal with the LATP solid electrolyte, circumventing the reduction of LATP by Li metal. At the positive electrode side, the PIN layer prevents the migration of polysulfides to the surface of LATP, preventing the reduction of LATP by polysulfides.     

Single‐Phase Mixed Transition Metal Carbonate Encapsulated by Graphene: Facile Synthesis and Improved Lithium Storage Properties

Transition metal carbonates (TMCs) with complex composition and robust hybrid structure hold great potential as high‐performance electrode materials for lithium‐ion batteries (LIBs). However, poor ionic/electronic conductivities and large volume changes of TMCs during lithiation/delithiation processes have hindered their applications. Herein, single‐phase Mn? Co mixed carbonate composites encapsulated by reduced graphene oxide (Mn_xCo_1?xCO₃/RGO), in which Mn and Co species are distributed randomly in one crystal structure, are successfully synthesized through a facial liquid‐state method. When evaluated as LIB anodes, the Mn_xCo_1?xCO₃/RGO composites exhibit enhanced electrochemical performance compared with the reference CoCO₃/RGO and MnCO₃/RGO. Specifically, the Mn_0.7Co_0.3CO₃/RGO delivers an ultrahigh capacity of 1454 mA h g^?1 after 130 cycles at 100 mA g^?1 and exhibits an ultralong cycling stability (901 mA h g^?1 after 1500 cycles at 2000 mA g^?1). This is the best lithium storage performance among carbonate‐based anodes reported up to date. Such superb performance is attributed to the hybrid structure and enhanced electroconductivity due to the integration of Co and Mn into one crystal structure, which is complemented by electrochemical impedance spectroscopy and density functional theory calculations. The facile synthesis, promising electrochemical results, and scientific understanding of the Mn_xCo_1?xCO₃/RGO provides a design principle and encourages more research on TMCs‐based electrodes.