The tributylphenyltin (TBPT)-encapsulated resorcinol (R)-formaldehyde (F) sol was prepared inside the micelles of cetyltrimethylammonium bromide (CTAB). This core-shell-type sol was polymerized and further carbonized to obtain nanosized Sn-encapsulated spherical hollow carbon. The size of spherical hollow carbon and Sn metal particles was controllable by changing the R/CTAB or TBPT/CTAB mole ratio, respectively. It is likely that, when tested as the anode in Li secondary batteries, the spherical hollow carbon acts as a barrier to prevent the aggregation of nanosized Sn particles and provides a void space for Sn metal particles to experience a volume change without a collapse of carbon shell, giving rise to a better cycle performance than that of pure Sn metal.

Three‐dimensionally ordered macroporous (3DOM) materials are composed of well‐interconnected pore and wall structures with wall thicknesses of a few tens of nanometers. These characteristics can be applied to enhance the rate performance of lithium‐ion secondary batteries. 3DOM monoliths of hard carbon have been synthesized via a resorcinol‐formaldehyde sol–gel process using poly(methyl methacrylate) colloidal‐crystal templates, and the rate performance of 3DOM carbon electrodes for lithium‐ion secondary batteries has been evaluated. The advantages of monolithic 3DOM carbon electrodes are: 1) solid‐state diffusion lengths for lithium ions of the order of a few tens of nanometers, 2) a large number of active sites for charge‐transfer reactions because of the material's high surface area, 3) reasonable electrical conductivity of 3DOM carbon due to a well‐interconnected wall structure, 4) high ionic conductivity of the electrolyte within the 3DOM carbon matrix, and 5) no need for a binder and/or a conducting agent. These factors lead to significantly improved rate performance compared to a similar but non‐templated carbon electrode and compared to an electrode prepared from spherical carbon with binder. To increase the energy density of 3DOM carbon, tin oxide nanoparticles have been coated on the surface of 3DOM carbon by thermal decomposition of tin sulfate, because the specific capacity of tin oxide is larger than that of carbon. The initial specific capacity of SnO2‐coated 3DOM carbon increases compared to that of 3DOM carbon, resulting in a higher energy density of the modified 3DOM carbon. However, the specific capacity decreases as cycling proceeds, apparently because lithium–tin alloy nanoparticles were detached from the carbon support by volume changes during charge–discharge processes. The rate performance of SnO2‐coated 3DOM carbon is improved compared to 3DOM carbon.

The high temperature lithiation behavior of the MoO2 electrode is examined, which is lithiated by one-electron reduction (by addition reaction) at room temperature. At elevated temperatures, this electrode is lithiated with four-electron reduction by addition and continued conversion reaction. As a result of four-electron reduction, the initial crystalline MoO2 phase is decomposed into a nanosized mixture of metallic Mo and Li2O , which is in turn converted to nanosized MoO2 upon forthcoming delithiation. An interesting feature here is that as-generated nanosized MoO2 is now fully lithiated up to four-electron reduction even at room temperature. This phenomenon is named “thermoelectrochemical activation” because the extension from one- to four-electron reduction is achieved by a simple charge–discharge cycling made at elevated temperatures. The thermoelectrochemically activated MoO2 electrode delivers a reversible specific capacity that is close to the theoretical four-electron capacity (838mAhnormalg−1) with an excellent cycle performance at room temperature.

Spherical Sn-carbon core-shell powder was synthesized through a resorcinol-formaldehyde ͑RF͒ microemulsion polymerization performed in the presence of hydrophobized Sn nanoparticles. The Sn-carbon core-shell structure was found to greatly enhance the cycle life compared to the mixture of Sn and spherical carbon when evaluated as the anode in lithium-ion batteries. A core-shell powder containing 20 wt % Sn showed 69% capacity retention at the 40th cycle when cycled between 0 and 2.0 V ͑vs Li/Li + ͒ at a constant current of 40 mA g −1. The mixture of 20 wt % Sn nanopowder and 80 wt % spherical carbon powder exhibited only 10% capacity retention in the same test condition. It is believed that the improved cyclability achieved with the core-shell powder is largely attributed to the inhibition of aggregation between Sn nanoparticles. The marginal polarization due to an intimate electrical contact made between Sn core and carbon shell is an additional advantageous feature achieved with this electrode.

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