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Biomass-derived materials offer low carbon approaches to energy storage. High surface area SiC w/wo 13 wt% hard carbon (SiC/HC, SiC/O), derived from carbothermal reduction of silica depleted rice hull ash (SDRHA), can function as Li+ battery anodes. Galvanostatic cycling of SiC/HC and SiC/O shows capacity increases eventually to >950 mA h g−1 (Li1.2–1.4SiC) and >740 mA h g−1 (Li1.1SiC), respectively, after 600 cycles. Post-mortem investigation via XRD and 29Si MAS NMR reveals partial phase transformation from 3C- to 6H-SiC, with no significant changes in unit cell size. SEMs show cycled electrodes maintain their integrity, implying almost no volume expansion on lithiation/delithiation, contrasting with >300% volume changes in Si anodes on lithiation. Significant void space is needed to compensate for these volume changes with Si in contrast to SiC anodes suggesting nearly competitive capacities. 6Li MAS NMR and XPS show no evidence of LixSi, with Li preferring all-C environments supported by computational modeling. Modeling also supports deviation from the 3C phase at high Li contents with minimal volume changes.